general chemistry chemistry

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ÎÖ Chemistry Experiment’s

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Preface

Praise we prayed to the divine presence Allah SWT who has given his blessing and gift to

us all.

Thank Allah SWT, the Chemistry Experiment’s book for chemistry program has to be

resolved. This Chemistry Experiment’s book is a reference for students of chemistry

program of Department of Natural Science Education in Faculty of Tarbiya’ and Teaching

Science in performing chemistry experiments related to general chemistry lecture material.

My gratitude goes to all those who have helped guide the completion of the Chemistry

Experiment’s book, especially for those majoring in Department of Natural Science

Education - Faculty of Tarbiya’ and Teaching Science – Syarif Hidayatullah Islamic State

University.

Hopefully this book can be useful for all of us. Amiinn.

Author


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Content

Preface .............................................................................................................................. 1

Contents ........................................................................................................................... 2

Laboratory Rules ............................................................................................................... 3

Safety and Health in Laboratory ....................................................................................... 5

Experiment I ...................................................................................................................... xx

Observation Data Sheet .................................................................................................... xx

Experiment II ..................................................................................................................... xx


Experiment III .................................................................................................................... xx


Experiment IV .................................................................................................................... xx


Experiment V ..................................................................................................................... xx


Experiment VI .................................................................................................................... xx


Experiment VII ................................................................................................................... xx



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1. Before entering the laboratory, students must use a laboratory coat

2. Each group is required to bring equipments consisting of :

• One sheet of hand wipes

• One sheet of rag mop

• fire lighters

• Hands soap

• Pipet drops

• Tissue

3. In experiments, students must be accompanied by lecturers and or laboratory officer

and or assistant

4. Before doing the experiments, students borrow the tools from laboratory officer and

fill and signed administration book

5. Students are responsibility to all equipment that borrowed, and should be checked

first before the experiments begins. If there is a damaged appliance be reported

immediately to the laboratory officer

6. During the experiments progresses, the workplace of each group must be kept clean

7. Cautions !! not allowed to smoke and eat

8. During the experiments, students expected ,always, to be careful and prudent in the

use of chemicals


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9. After the experiments is completed, the workplace of each group must be clean and

dry

10. After the experiments, the tools should be returned to the laboratory officer in a

clean and dry, and fill out and sign the administration book

11. After the experiments, each group must show the results of experiments to assistant

and legalized it, one for archive

12. Equipment that is broken intentionally or unintentionally caused by student should be

recorded in administration book and should be replaced in accordance with the

specification tool, not later than two weeks

13. Each student must submit an experiments report not later than one week after the

experiment conducted

14. Dispose of trash in the trash bag


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The laboratory is a workplace to conduct scientific research. The laboratory is also

used as a means of experiments for students in a supportive learning done in class.

Chemistry laboratory as a means of chemistry laboratory course can not be separated from

the chemicals and laboratory activities that require the attention of safety.

In carrying out students activities in the chemistry laboratory, must be considered

regarding safety. Chemistry laboratories should be sought is a safe place to work and free

from fears of accidents. The students and laboratory officer jointly responsible for

administering occupational health and safety in the laboratory, in order to do experiments

effectively and efficiently.

Here are a few types and signs of the materials or chemicals that need to be

considered :

Classification Symbol

Toxic chemicals are chemicals that can

cause harm to humans or cause death if

inhaled into the body by being

swallowed, passing through the

respiratory or skin contacts. Examples:

benzene, cyanide, chromium, lead,

asbestos dust

Corrosive chemicals are chemicals that

cause damage to living tissue. Examples:

sulfuric acid, phenol, formaldehyde


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Flammable chemicals are chemicals that

easily react with oxygen and cause a fire.

Example: acetone, phosphorous, benzene,

hexene, di ethyl ether

The chemical explosive is a solid or

liquid substance or mixture of both that

due to chemical reaction to produce gas

and pressure of spontaneously giving rise

to damage. Example: trinitrotoluen,

nitroglycerine, ammonium nitrate

Oxidizing chemicals are chemicals that

can produce oxygen so that other

materials may cause fire. Example:

potassium chlorate, potassium

permanganate, hydrogen peroxide

Irritation chemicals are chemicals that

can cause inflammation / irritation of the

skin, eyes, and breathing. Example: zinc

sulfate, potassium permanganate, silver

nitrate

Chemicals that can pollute / damage the

environment if the waste directly into the

environment without any processing


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Chemical Safety Guidelines Data

The term for data safety guidelines for chemicals that are used internationally is the

Material Safety Data Sheets (MSDS). In the MSDS guidelines, there are four signs that

must be considered. Blue columns indicate the level of a chemical hazard to health. Red

columns indicate the level of a chemical hazard to the fire. Yellow column showed level

chemical reactivity. White Columns is a special sign for some chemicals.

Figure 1. Symbol of substances / chemicals on the MSDS data

First aid in the laboratory

Accidents in the laboratory are not expected to occur even if the pattern has been

applied to K3. Therefore, in doing laboratory work, students and officers need to have

knowledge about the steps to be taken in case of accidents. First aid (P3K) is knowledge

that must be possessed by every students as the prevention of accidents are more severe

impact before getting intensive treatment from the doctor.

Here are some kinds of accidents in the laboratory and handling.

1. Burn

If the body burns due to heat, basting with livertran ointments, butter or pikrat 3%

acid solution. If the wound is large enough flush with 1% bicarbonate solution and

immediately take it to the nearest clinic.


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2. Skin exposed to concentrated acid

If the skin is exposed to splashing Sulfuric acid, or Nitric acid, immediately wiped

with tissue paper and then wash with water and Sodium bicarbonate. Drain and spread

with ointment livertran.

3. Skin exposed to strong base

Immediately wash with tap water that much, then with 1% Acetic acid solution

and rinse again with water. After dry rubbing with ointment livertran.

4. Skin exposed to bromine water

Immediately wash with Benzene and basting with the Glycerine. After a while

washing the rest of glycerin with water and spread with ointment livertran.

5. Skin exposed to organic substances

If the skin is exposed to the corrosive organic substance, wash it with Alcohol,

then wash again using soap and warm water.

6. Eyes affected by acid / base

a. If dilute acid, wash the eye with a solution of Sodium bicarbonate 1% using eye

wash equipment.

b. If a concentrated acid, first wash with water as much as possible, then wash with a

solution of Sodium bicarbonate 1%.

c. If the eyes exposed to alkali, washing with water and 1% Boric acid solution.

7. Solids, liquids, and toxic gases

a. If the toxic substances into the mouth but not swallowed. Substance is released

immediately and rinse with water as much as possible.

b. If the acid solution ingested, immediately drink water as much as possible. Then

drink water slurry of lime or magnesia and pure milk. If a strong base which is

swallowed, immediately drink as much as possible, then drank a solution of

diluted vinegar, lemon juice, lactic acid, after that drink whole milk.

c. Arsenic or Mercury compounds are swallowed, promptly drink salt solution made

by dissolving one teaspoon of salt in a glass of warm water.


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d. If inhaled chlorine gas or bromine, open upper garment immediately inhale

ammonia or gargle with a solution of bicarbonate. Furthermore, menthol smoke or

drink hot liquids like peppermint.

Terms - conditions of storage material

In applying the pattern of K3 in the laboratory, need to be considered also on

storage of chemicals. This is intended to avoid the occurrence of fire, explosion, or leakage

of chemicals. Effect of heat / flame, the effect of moisture, interaction with the container,

the interaction with light, and the interactions between chemicals should be considered in

storage. As already noted earlier on the types and signs of chemical, then some way of

storing chemicals described as follows.

1. Flammable chemicals stored at low temperature and ventilated, kept away from

sources of ignition. Example: ether, alcohol, acetone.

2. Corrosive chemicals are stored in low-temperature room, a sealed container and

separated from toxic substances. Example: alkali metals, acid anhydride.

3. Toxic chemicals are stored in low-temperature room, away from the danger of fire,

separated from other materials that might react. Examples: cyanide, phosphorus,

arsenic.

4. Irritant chemicals stored in confined spaces, low temperature, and in isolation from

student. Examples: silver nitrate, Sodium hydroxide, barium chloride.

5. Oxidizing chemicals are stored in low temperature space, ventilated, kept away

from sources of ignition, material or kept away from flammable liquids. Example:

perchlorate, permanganate, peroxide.

6. Pressurized gas stored in a state of standing upright and vertical, kept away from

the fire, kept away from corrosive materials. Example: nitrogen gas, acetylene,

hydrogen, etc..

Laboratory Techniques

Implementation of an effective working atmosphere and efficient can be realized by

observing the pattern of occupational safety and health (K3) in doing the work in the


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laboratory. Laboratory techniques and skills is needed in order to realize this. The

following will be shown some basic skills of science laboratory technique.

1. Measuring the volume of solution:

Volumetric glassware is used for precise and

accurate volumes. The types of volumetric glassware

you will use are volumetric flasks, volumetric pipets

and burets. Flasks and pipets are in your locker while

burets are located at your workbench or in one of the

fume hoods.

To read the liquid level in all of these, find the bottom of the meniscus and read

accurately from the graduations on the vessel. With volumetric flasks/pipets, align the

bottom of the meniscus with the etched mark. When you do this, make certain that your

eye is at the same level of the meniscus to avoid error due to parallax. Be sure to wear

gloves when rinsing the volumetric pipet with the solution.

Volumetric pipets, like our 10 mL one, are used to transfer liquids or aqueous

solutions. Always use a rubber bulb to fill pipets. It has a fixed silicone rubber adapter that

can take pipets of different sizes. If you accidentally let a liquid or solution get into the

bulb, empty the bulb at once and try to dry it with Kim wipes.

The first step is to rinse the pipet with deionized water. Pour deionized water into a

beaker. Squeeze the end of the bulb with one hand and gently place the pipet inside it.

Apply a gentle downward pressure on the bulb to make an airtight seal, and squeeze out

some of the air in the bulb. Place the tip of the pipet into the beaker and ease up on the

squeezing to draw water into the pipet until its approximately half full. Have your index

finger or thumb ready to quickly place it on the opening of the pipet as soon as you remove

the bulb from the pipet. This prevents the water from running out. Turn the pipet horizontal

and gently roll it so the water wets the entire inside surface. Once you're finished rinsing,

drain the pipet in the sink.

Before you can use the pipet to transfer your solution, you should rinse it with the

solution. Pour the solution into a beaker. Attach the pipet to the bulb as you did in step 1.

Place the tip of the pipet into the beaker and draw solution into the pipet by releasing


Figure 2. Meniscus of solution

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pressure on the bulb. Once it's filled halfway, remove the bulb and quickly place your

index finger on top. Turn the pipet horizontal and gently roll it to wet the inside surface.

Discard the rinse solution into an appropriate waste container. After one rinsing (or two if

desired), the pipet is ready for use.

Make sure you have enough solution in your beaker and have the beaker to which

you will transfer the solution handy. As you did in steps 1 and 2, attach the pipet to the

bulb to draw the solution into the pipet. Avoid drawing the solution into the bulb. This time

you need to draw enough solution so that the meniscus is above the etched mark. Remove

the bulb and quickly place your index finger on top of the pipet.

Note that if you don't draw enough solution into the pipet, you may have to squeeze

the bulb again at least once to draw in enough solution. Remember to use your finger to

hold the solution in.

Remove the pipet from the solution, and wipe the pipet's tapered end with a Kim

wipe. Then, holding the pipet in one hand and the waste container in the other, let the

tapered end of the pipet touch the edge of the beaker. Bring the meniscus to your eye level

and release your finger slightly from the top of the pipet so the meniscus drops slowly to

the etched mark. When you think the bottom of the meniscus reaches the etched mark,

reassert pressure on the top of the pipet. There should be exactly 10 mL of solution in the

pipet.

With the pipet in one hand and the beaker into which you want to transfer the

solution in the other, place the tip of the pipet on the edge of the beaker. Remove your

index finger from the top of the pipet so the solution flows into the beaker.

After draining the solution into the beaker, you will notice a small amount of liquid

in the end of the pipet. Since this pipet is marked 'TD,' meaning 'To deliver,' the small

amount of liquid remaining at the tip should not be blown out.


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2. How to Fold Filter Paper

Filter paper is paper specially designed with "pores" so it can be used to separate a

component from a mixture. Filters used in everyday life, such as in coffeemakers or

furnaces, are easy to use. In a laboratory, however, the basic piece of filter paper is

circular-shaped, and it must be folded before it can be used in a funnel.

a.The basic filter paper used in the laboratory is a flat, circular-shaped paper that feels something like construction paper. If it is a new piece of filter paper, it will be perfectly flat with no folds or creases.

b.

Fold your piece of filter paper in half. It will have the shape of half of a pizza.

c.

Fold your piece of filter paper in half again. It now has the shape of one-fourth of a pizza.

d.Your filter paper is now folded into four layers. To use the filter paper, open it up into a cone shape, with three layers on one side of the cone and one layer on the other. It will have a cone shape.

e. Your folded filter paper is now ready to use. You should wet the filter paper before you place it into the funnel. The seal that is created between the funnel and the wet filter paper will actually quicken the filtering process. Set it inside a funnel to give it support.


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Do not poke holes in your filter paper. Filter paper has pores already, and even though you may not be able to see them, they are designed to pass substances that are small enough. This is why you can buy different types of filter paper, depending on the size of the substance you want to pass through.

3. Smelling chemicals or solutions

To recognize the smell of a substance that evaporates easily done by placing the

container substance / tube ± 25 cm from the nose. Shake off steam at the top of the

container by hand so that they can smell the smell.

Figure 3. Smelling chemicals or solutions

4. Heating Substances

Eye protection should be worn whenever a substance is heated !!.

Heating substances is always exciting but it is essential to keep the amounts used

to a minimum and to use the correct apparatus in the recommended manner.

Although improvised containers can be used, the notes here refer only to the pieces

of laboratory apparatus most commonly used for heating substances:

ignition tubes (small test-tubes);

test-tubes;

boiling tubes (large test-tubes);

beakers;

evaporating basins;

crucibles.


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Heating solids in test–tubes

Wear eye protection. Only fill to a maximum of 1/5 full. Use

a suitable test-tube holder. Hold the test-tube at a slight angle (see

diagram). Ensure that the open end of the test-tube isn’t pointing

directly at anybody. Hold the test-tube so that the bottom is just in

the tip of the flame. Always start heating with a small, gentle flame.

Heating liquids in test tubes

Wear eye protection. Use a boiling tube (wide diameter) and

do not fill to more than 1/10 full. Add an anti-bumping granule to

give smoother boiling. Add the granule before starting to heat. Use a

suitable holder. Hold the tube at an angle so that the top is well away

from the flame.

Hold the test-tube so that the bottom is just in the tip of the

flame. Keep the liquid in the tube moving gently. For flammable liquids, use a water bath.

Heating flammable liquids

Wear eye protection. Use a boiling tube (wide diameter) and do

not fill to more than 1/10 full. Add an anti-bumping granule to give

smoother boiling. Add the granule before starting to heat.

DO NOT heat directly over a naked flame. Stand the tube in a

beaker of hot water (e.g. from a kettle or hot tap).

Heating in beakers (and conical flasks)

Beakers should only be filled to 1/3 of their capacity when used for heating liquids.

The addition of a few ‘anti-bumping’ granules will ensure smoother boiling.

Heating in evaporating basins

A flat-bottomed evaporating basin can be heated by supporting it on a wire gauze

on a tripod. A round-bottomed evaporating basin is very unstable on a wire gauze so

should be supported on a pipe-clay triangle when heating.


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Evaporating basins should be filled to between 1/3 and 1/2 full.

When evaporating salt solutions, the solution should be heated (with occasional

stirring using a glass rod), until solid just appears evenly around the edge of the liquid. The

solution can then be left to cool - possibly overnight (labelled with names of the owners,

the chemicals and any relevant safety warnings).

Heating in crucibles

A crucible must be heated on a pipe-clay triangle and not on a gauze. Start with a

small, gentle flame before gradually increasing the heating rate. Allow plenty of time in the

lesson for crucible and contents to cool down.

5. Pouring chemicals

a) Pouring liquids

Always read the label on a reagent bottle before using its contents.

Always wear safety goggles when using an open flame or handling chemicals.

Never touch chemicals with your hands.

Never return unused chemicals to their original containers. To avoid waste, do

not take excessive amounts of reagents.

Follow these procedures, demonstrated by your teacher when pouring liquids:

Use the back of your fingers to remove the stopper from a reagent bottle. Hold the

stopper between your fingers until the transfer of liquid is complete. Do not place

the stopper on your workbench.

Grasp the container from which you are pouring with the palm of your hand

covering the label.

When you are transferring a liquid to a test tube or measuring cylinder, the

container should be held at eye level. Pour the liquid slowly, until the correct

volume has been transferred.

When you are pouring a liquid from a reagent bottle into a beaker the reagent

should be poured slowly down a glass stirring rod. When you are transferring a

liquid from one beaker to another, you can hold the stirring rod and beaker in one

hand.


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Figure 4. Pouring the solution from reagent bottle

b) Pouring solids

In pouring chemicals in the form of solids, provide a piece of paper ± 15 cm

wide and 2 cm, then insert into a test tube with leaves ± 1.5 cm above the mouth

of the tube. Pour solids on the paper. Next, hold the paper and straighten the

upper end of vertical tube, and lift the paper.

Figure 5. Pouring solids to the test tube

6. Dilution of concentrated acid

In conducting dilution of concentrated acid or liquid chemicals that are

exothermic, heat generated note. First, prepare a beaker or other container which already

contains the distilled water that has been calculated according to the volume dilution of


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concentration desired. Then take the concentrated acid using volumetric pipet with bulb

pipet in accordance with the volume of the desired concentration. After that, slowly pour

through the walls of the beaker until the concentrated acid at low volumetric pipet.

CAUTION !! use rubber gloves, goggles, and masks. Do as possible in the acid room.

7. Balance

When a balance is required for determining mass, you will use a centigram

balance. See figure below. The centigram balance is sensitive to 0.01 g. This means that

your mass readings should all be recorded to the nearest 0.01 g.

Before using the balance, always check to see if the pointer is resting at zero. If the

pointer is not at zero, check the slider weights. If all the slider weights are at zero, turn the

zero adjust knob until the pointer rests at zero. The zero adjust knob is usually located at

the far left end of the balance beam. See Figure 1-5. Note: The balance will not adjust to

zero if the movable pan has been removed. Whenever weighing chemicals, always use

weighing paper or a glass container.

Figure 6. Centigram balance ( O Hauss balance)

Never place chemicals or hot objects directly on the balance pan. They can

permanently damage the surface of the balance pan and affect the mass weighing.

In many experiments you will be asked to weigh out a specified amount of a

chemical solid.


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CAUTION Do not touch chemicals with your hands. Always wear gloves,

apron, and safety goggles when handling chemicals. Carefully check the label on

the reagent bottle or container before removing any of the contents. Never use

more of a chemical than directed; you should know the locations of the safety

shower and eyewash and how to use them in case of an accident.

Figure 7. Completness in the laboratory


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Purpose

Make a solution of NaCl / Harnstoff 0.2 M of 250 ml

Overview

In chemistry, a solution is a homogeneous mixture composed of only one phase. In

such a mixture, a solute is dissolved in another substance, known as a solvent. The

solvent does the dissolving. Homogenous means that the components of the mixture

form a single phase. The properties of the mixture (concentration, temperature, density,

etc.) can be uniformly distributed through the volume but only in absence of diffusion

phenomena of after their completion. Usually, the substance present in the greatest

amount is considered the solvent. Solvents can be gases, liquids, or solids. One or more

components present in the solution other than the solvent are called solutes. The solution

has the same physical state as the solvent.

It is common practice in laboratories to make a solution directly from its constituent

ingredients. This requires determining the right amount of solvent/solute for specific

concentration. There are three cases in practical calculation:

Case 1: amount of solvent volume is given.

Case 2: amount of solute mass is given.

Case 3: amount of final solution volume is given.

In the following equations, A is solvent, B is solute, and C is concentration. Solute volume

contribution is considered through ideal solution model.

Case 1: amount (ml) of solvent volume VA is given. Solute mass mB = C VA dA /(100-

C/dB)


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Case 2: amount of solute mass mB is given. Solvent volume VA = mB (100/C-1/ dB )

Case 3: amount (ml) of final solution volume Vt is given. Solute mass m B = C Vt

/100; Solvent volume VA=(100/C-1/ dB) mB

Case 2: solute mass is known, VA = mB 100/C

Case 3: total solution volume is know, same equation as case 1. VA=Vt; mB = C VA

/100

Materials and apparatus

Apparatus Materials

O Hauss balance 10 ml Volumetric pipet Table saltSpatula 100 ml beaker glass Harnstoff Watch glass Tripod and asbestos gauze Aquadest 200 mL beaker glass Alcohol burnerStirer bar Wash bottleGlass funnel Filter paper250 ml Volumetric flask Mortar and pestleStative and ring

Procedures :

1. For the 250 ml 0,2 M Sodium Chloride solution, calculate the mass of Sodium

Chloride. Mass of Sodium Chloride is .............. grams.

2. Fill 250 ml beaker glass with Sodium Chloride wich has been weighed. Add 150-

200 ml aquadest, than stirer until all salt dissolve. Afterward, filter the solution

using filter paper.

3. Pour the salt into volumetric flask, then add aquadest to mark boundaries. Shake

until homogeneous.

4. Take 200 ml of solution in the flask, and enter into a 200 ml beaker. Then take 50

ml of solution using a volumetric pipet, then enter into a 100 ml beaker.

5. Heat the solution using a medium heat until crystals formed. Weigh the crystals

formed. Mass of crystal is ........... grams.

6. Take few of crystal and observed under microscope. Sketches of crystal formed.


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Pre lab questions

1) What is the function of volumetric flask in these experiments? Why using

volumetric flask not another measure tools?

2) in making 100 ml CaCO3 2M solution, how many grams CaCO3 that must be

weighed?

3) What is crystal and crystallization?

Post lab questions

1) Mentioned usefulness of saltpeter in daily life.

2) Write the procedure for making 250 ml CuSO4 1M solution.

3) Calculate the KIO3 in table salt.

4) What shape of crystal that yield from experiment.

OBSERVATION DATA SHEET

Title :

Date :


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Purpose :

Sketch of Procedure Observations

Initial mass of Sodium Chloride :

Crystal mass of Sodium Chloride :

Shape of Sodium chloride crystal :

Sketches of crystal shape :


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Calculation :

Analysis of data :


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Conclusion :

TangSel, .............................., 20.....Assistant

..................................................


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Purpose :

Perform the process of separation and refining of liquids by distillation and

extraction.

Perform the process of purification of solids by sublimation.

Perform separating of liquids by paper chromatography

Overview :

The process of separation and purification of a substance from other substances

that are not desirable, is a very important process in the manufacture of a compound.

There are various ways of separation and purification of a substance from the physicall

mixtures, among others:

liquid-liquid separation can be done by distillation, extraction, and coagulation

solid-liquid separation can be done by decantation, filtration, adsorption, and

distillation

Some of the separation process to be performed on this experiment, among others:

1. Distillation

Distillation is the process of separation and purification of substances based on

differences in boiling point of each substance. Vapor pressure is one physical trait that

each liquid. At the boiling liquid, vapor pressure equal to the outside air pressure. At this

temperature all the molecules of liquid have enough energy to turn into the gas phase. In

distillation, the gas formed is cooled through a condenser and then accommodated. The

existence of differences in boiling points of substances in a mixture, each substance will

be collected at different temperatures, allowing the separation and purification of certain

substances. Better separation would occur if each agent has a boiling point difference is


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quite large. Various kinds of distillation processes include distillation terraced, vacuum

distillation, etc..

2. Extraction

Extraction is the process of taking substances from mixtures based on differences in

solubility of the substance between two solvents are not mutually interfere. In this

process, a solvent is added to the mixture so that the desired substance is soluble, but

other substances in the mixture should not come late, so that these substances can be

separated from the mixture. In the extraction process used separating funnel and shaking.

3. Sublimation

Sublimation is the process of purification of solids by heating so that the substance

may change phase directly from solid phase into the gas phase and back again to the solid

phase in the prepared container. This process is very effective for purifying certain solids

because of its ability to change phase from solid to gas is not owned by the impurity-

substances, so that the products being stored can be ascertained from this process is

pure.

4. Paper chromatography

Chromatography is a method used to separate molecular mixtures based on the

distribution of molecules in the mixture with the stationary phase (adsorbent) and mobile

phase (eluent). Distribution of the phase distribution of molecules can be either

adsorption or partition the phase distributions.



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Apparatus : Distillation set, Separating funnel, 250 ml Erlenmeyer flask, Beaker glass,

Stirer bar, Pipet droper, Mortar and pestle, Glass funnel, Filter paper, Stative, clamp dan

ring, Watch glass, Tripod and asbestos gauze, Measurement cylinder, wash bottle.

Materials : Iodine, n-hexane, Naphtalene, Ice cube, Chloroform, Aquadest, Methanol, Marker.

Procedure :

Distillation

1. Arrange a tool such as a picture set of tools distillation. Note the flow of water in the

condenser!.

2. Take 100 ml of sample solution, then pour into the distillation flask using a funnel.

3. Enter a boiling stone, and then heat the flask.

4. Record the temperature when destilat began to trickle and watch the trend of rising

temperatures.

5. Stop heating when the liquid in the flask is low so destilat uncontaminated and easily

cleaned pumpkin.

Extraction

1. Weighing 0.005 g I2 and then insert it into the erlenmeyer flask.

2. Adding 30 ml of water, stir the solution, and enter into a separating funnel.

3. Add 30 ml chlorofrom (CHCl3), and shake thoroughly for 5 minutes with occasional

uncorked.

4. Squelch a few minutes so as to form two layers.

5. Separates the bottom layer with top layer and stored in two different containers.

6. Adding back Chlorofrom in water solution remaining in the separating funnel,

shake for several minutes, then set aside some time.

7. Separating the back between the bottom layer with top layer.

8. Calculate the concentration of iodine in the extraction of 1x and 2x extraction.

Sublimation

1. Enter the gross that has been refined Naphthalene in 100 ml beaker.


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2. Close the beaker with a watch glass.

3. Put ice on a watch glass.

4. Heat the beaker gently using a hotplate or burner methylated. Naphthalene will

vaporate and then crystallized at the bottom of the watch glass.

5. When finished collect the crystals formed. Note the difference in appearance

before and after the Naphthalene sublimation.

Chromatography

1. Cut filter paper to the size of p = 9cm; l = 2cm. make a point of using colored

markers.

2. Enter a ± 5 ml of solvent into the container.

3. Insert the filter paper into the container to touch the paper base solution. Then

hang over the mouth of the container.

4. Observe the changes that occur, then calculate its Rf.

Analisis data

Analyze the data obtained, such as when the temperature begins to drip and color

destilat; physical shape of each layer in the extraction phase; physical form crystals before

and after sublimation; count on a chromatographic Rf. Compare data with references that

you know and point out your argument about that fact.

Series of tools


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Questions

Pre-lab questions

1. What is the boiling point?

2. Is the function of the boiling rock?

3. Name the distillation process applications in the life or industrial? explain!

4. What are the criteria used for the extraction solvent?

5. What are polar and non polar solvents?

6. Mention of other solid substances which undergo a process of sublimation (3)?

Post-lab questions


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1. Is a simple distillation can be used to separate liquids with boiling points of adjacent?

if not, what alternatives do you suggest?

2. Which produces better separation: 20 ml of the mixture is separated using 100 ml of

solvent with a one-time, or 20 ml of the mixture were separated using 20 ml of

solvent with 5 times the process? why?

3. Explain how crystals can form in the watch glass? whether the sublimation process

can be applied to all solids?

4. Why in the chromatography experiments formed a different color from the color of

the origin of the markers?



31

Title :Date :Purpose :

Distillation

Sketches of procedures Observation

Volume of sample :


32

color of solution before distillation :

color of solution after distillation :

Temperature of destilat start trickling :

Extraction


Before extraction


33

Color of I2 solution :

Color of chloroform :

After extractionColor of the upper layer :

Color of the bottom layer :

Sublimation


Before sublimation Color of the crystal :


34

Shape of crystal :After sublimation Color of crystal :

Shape of crystal :

Paper chromatography


Marker color :


35

Colors after separation :

Analysis of Data :


36

Conclusion :

TangSel, ............................. 20......Assistant

.........................................


37

Purpose

1. Making standard solution (Oxalic acid) to standardize Sodium hydroxide solution

2. Determining the molar mass of the titrated acid solution

Overview

Find out the references about the acid-base titration (i.e. standard solution, type

of standard solution, titration curve, titration end point, etc.) from chemistry for college

textbook and another references, i.e. handbook, website !. References should be taken

from two textbook of chemistry for college.

Material and apparatus

Apparatus : Materials : 250 ml volumetric flask 200 ml beaker glass 100 ml beaker glass 50 ml buret Glass funnel 25 ml volumetric pipet Drop pipet

250 ml erlenmeyer flask

Stirer bar Analytical balance wash bottle Stative and clamps Spatula

Oxalic acid 0,05M NaOH 0,1 M White Vinegar Limo orange Aquadest Phenolfthalein

Procedures

Part I : Preparation of a primary standard acid

1. Before coming to thr laboratory, calculate the mass of Oxalic acid. H2C2O4.2H2O

that you will need to make up 250 ml of a 0,0500 M solution.

2. Put on your lab apron and safety googles.

3. Top load the amount of Oxalic acid that you have calculated into a 100 ml beaker


38

and accurately record the mass ot the Oxalic acid in the table. Do not spend too

much time trying to get exactly the same mass as you calculated. The important

things is to record accurately the mass you do have and to calculate the molarity

of Oxalic acid from this mass. For example, the mass you use may give the solution

a molarity of 0,0496 M. This is perfectly acceptable, provided that you use this

figure in your calculations.

4. Dissolve the Oxalic acid in water, and pour the solution through a funnel into a

250 ml volumetric flask. Wash the beaker with water twice, and add these

washngs to the flask. Now add water to the flask until the level is up to the mark.

Use a wash bottles you get closer to the mark. Stopper the flask, and shake to

ensure the solution is homogeneous. You now have your standard solution of

Oxalic acid.

Part II : standardization of an unknown NaOH solution

1. Obtain a 100 ml beaker and fill it with NaOH solution of unknown molarity. Label it

NaOH.

2. Add about 15 ml of the NaOH solution solution to the buret through a funnel,

rinse it back and forth, and then discard it through the tip into the sink. Repeat.

3. Fill up the buret with more NaOH solution and allow some to drain in order to

remove any air bubbles in the tip. Remove the funnel.

4. Using the suction bulb on the end of your pipet, withdraw about 5 ml of Oxalic

acid, rinse it around pipet, and discard it. Repeat. Withdraw 25 ml of the standard

Oxalic acid solution and transfer it to a 250 ml erlenmeyer flask. The correct

volume is delivered when you have touched the tip of the pipet to the side of the

flask. Do not blow through the pipet. (Note : NEVER pipet from the volumetric

flask, you will have to transfer the Oxalic acid first to clean, dry 100 ml beaker and

then pipet out of the beaker).

5. Add 3 drops of Phenolphtalein solution to the acid in the erlenmeyer flask.

6. Read the initial volume of NaOH in the buret accurately and record it in the table.


39

Then open the valve on the buret. Allow the NaOH solution to run into the flask

and swirl constantly to ensure thorough mixing.

7. After a time, you will notice a pink color that appears where the NaOH solution

enters the liquid in the flask. When this color takes a longer time to disperse and

disappear, slow down the rate of addition of NaOH until eventually you are adding

it a drop at a time. Stop the titration when the faintest possible pink color stays in

the flask for about 20 s. Read the final volume of the NaOH in the buret and record

it in the table (the difference between the initial reading and the final reading

represents the volume of NaOH required to neutralize the Oxalic acid).

8. If you are at all in doubt as to whether you have a pale pink color, take the reading

anyway, then add one more drop. If the color immediately becomes darker, the

reading you took is probably the most accurate result. This is called the end point

of the titration. Discard the solution down the sink.

9. Pipet another 25 ml of Oxalic acid into the flask and again add 3 drops of Phenolph

talein. Refill the buret (if necessary) and repeat the titration. Run in NaOH to

within 1 ml of the volume needed in the first titration, then add the solution a

drop at a time, swirling after each drop, until you get the faint pink endpoint.

Repeat the titration until you have two readings that agree to within 0,08 ml.

Part III : determination of the molar mass of an unknown solid acid

1. Obtain a vial containing an unknown solid acid from your teacher. Record the

identifying number or letter in the table.

2. Weight out about 0,40 g of the solid acid into a clean, dry beaker, and record the

mass accurately into table. It does not have to be exactly 0,40 g as long as you

know exactly how much you have.

3. Dissolve the acid into approximately 40 ml of water and transfer the solution to an

erlenmeyer flask. Rinse the beaker twice to ensure that all the acid solution is

transferred (the amount of water added does not alter the results). Add 3 drops of

Phenolphtalein.


40

4. Run in NaOH from a buret as in part II, measuring the volume required to reach

the endpoint. Record this figure in table.

5. Repeat steps 2 and 4 until you get two readings in close agreement. If you do not

have exactly the same mass each time, check whether the results agree by

determining the ratio of the volumes and comparing it with the ratio of the

masses used.

Questions

Pre lab questions

The molarity of a hydrochloric acid solution can be determined by titrating a

known volume of the solution with a Sodium hydroxide solution of known

concentration. If 14.7 mL of 0.102 M NaOH is required to titrate 25.00 mL of a

hydrochloric acid, HCl, solution, what is the molarity of the hydrochloric acid?

Post lab questions

The molarity of a Sodium hydroxide solution can be determined by titrating a

known volume of the solution with a Hydrochloric acid solution of known

concentration. If 19.1 mL of 0.118 M HCl is required to neutralize 25.00 mL of a

Sodium hydroxide solution, what is the molarity of the Sodium hydroxide?



41


Part ISketches of procedures Observation

Calculated mass of Oxalic acid

Required for 250 ml of 0,050M solution (g)

Mass of Oxalic acid used (g)

Part II


42


Trial 1 Trial 2 Trial 3 Trial 4 (if necessary)

Initial reading of buret (ml)Final reading of buret (ml)Volume of NaOH required (ml)Average volume of NaOH (ml)

Part III


43

Unknown solid acid : ....................................


Trial 1 Trial 2 Trial 3 Trial 4 (if necessary)

Mass of acid (g)

Initial reading of buret (ml)Final reading of buret (ml)Volume of NaOH required (ml)Average volume of NaOH (ml)

Calculations :


44

Analysis of data :


45


46

Conclusion :

TangSel, ............................. 20......

Assistant

.........................................


47

Purposes

Observe the chemical changes indicative of chemical reactions

Overview

A chemical reaction is a process that leads to the transformation of one set of

chemical substances to another. Chemical reactions can be either spontaneous, requiring

no input of energy, or non-spontaneous, typically following the input of some type of

energy, viz. heat, light or electricity. Classically, chemical reactions encompass changes

that strictly involve the motion of electrons in the forming and breaking of chemical

bonds, although the general concept of a chemical reaction, in particular the notion of a

chemical equation, is applicable to transformations of elementary particles, as well as

nuclear reactions.

The substance (or substances) initially involved in a chemical reaction are called

reactants or reagents. Chemical reactions are usually characterized by a chemical change,

and they yield one or more products, which usually have properties different from the

reactants. Reactions often consist of a sequence of individual sub-steps, the so-called

elementary reactions, and the information on the precise course of action is part of the

reaction mechanism. Chemical reactions are described with chemical equations, which

graphically present the starting materials, end products, and sometimes intermediate

products and reaction conditions. Different chemical reactions are used in combination in

chemical synthesis in order to obtain a desired product. The characteristics of chemical


48

reactions are : Evolution of gas, Formation of a precipitate, Change in color, Change in

temperature, and Change in state.


Apparatus : Materials : Test tube Spatula Test tube proof Rubber tube Drop pipet

ZnSO4 0,1 M NH4OH 1M BaCl2 0,1 M K2CrO4 0,1 M HCl 0,1 M CaCO3 lumps

Oxalic acid 0,1M H2SO4 2 M KMnO4 0,05M FeSO4 0,1 M Aluminium foil HCl 3 M

Procedures

1. Precipitate formation

Zinc Deposition

a. Add 1 ml of 0.1 M ZnSO4 into a test tube, then add 1 ml of 1 M NH4OH Record

your observations!.

b. Add back in the tube above the solution with 1 M NH4OH little by little. Record

your observations! .

The precipitate Barium

a. Take 1 ml of 0.1 M BaCl2, enter into a test tube, then add 1 ml of 0.1 M K2CrO4

observe what happens.

b. Add 1 ml of 0.1 M BaCl2 solution into a test tube, then add into 1 mL of 0.1 M HCl

and then add another 1 ml of 0.1 M K2CrO4 Observe and record your

observations.

2. Reaction gas formation

a. Take 1 piece of tube and attach the hose pipe on the side of the tube to drain the

gas reaction products.

b. Put 2 grams of limestone (CaCO3) into the reaction tube at the top, then add 3

mL of 3M HCl, immediately close the tube with a cork / rubber and tebentuk gas

flowed into the clear water solution of Ba(OH)2. Notice what happens.


49

3. The reaction changes the color

a. Into a mixture of 1 ml of 0.1 M H2C2O4 and 2 drops of H2SO4, enter drop by drop

until the color of KMnO4 solution of KMnO4 is lost.

b. To a solution of 0.1 M FeSO4 add 2 drops of 2 M H2SO4, and add dropwise 0.1 M

KMnO4 Sprinkle 2 drops of 2 M H2SO4, and add dropwise 0.05 M KMnO4 Compare

the speed of color loss of KMnO4 in experiments 3a and 3b.

4. Reaction temperature changes

Exothermic

Enter into a test tube a small piece of aluminum foil. Then add 1 M HCl Observe the

changes that occur by holding the tube wall.

Endothermic

Enter into a test tube and a half tablespoons of harnstoff, then add water. Observe

the changes that occur by holding the tube wall.

Analysis of data

Write down the equation of each experiment performed.

Count the number of moles of precipitate formed during the experiment D1.

Count the number of moles of gas formed during the experiment D2.

Pre-lab questions

1. Mention the characteristics of chemical reactions.

2. What is the difference between endothermic and exothermic reactions?

3. Write the equation of chemical reaction that produces a color change, precipitate

formation, temperature changes, and gas formation. (Respectively 2).

Post-lab questions

1. In experiment D3, how the ratio of the speed loss in the second reaction of KMnO 4

color? explain!

2. What causes temperature changes in the experiment D4?

3. Mention examples of the four characteristics of chemical reactions in dayli life.


50



Precipitate formation



51

Zinc depositionChemical reaction Change after reaction

ZnSO4 + NH4OH

ZnSO4 + NH4OH + NH4OH

Precipitation of BariumChemical reaction Change after reaction

BaCl2 + K2CrO4

Chemical reaction Change after reaction

BaCl2 + HCl

BaCl2 + HCl + K2CrO4

Gas forming from reaction



52

Chemical reaction Change after reactionCaCO3 + HClvapor + Ba(OH)2

Color change from reaction



53

Chemical reaction Change that occur

H2C2O4 + H2SO4

H2C2O4 + H2SO4 + KMnO4

Reaction Change that occurH2C2O4 +H2SO4 + KMnO4 0.1 MH2C2O4 + H2SO4 + KMnO4 0.05 M

Temperatur change from reaction


ExothermicReaction Change occur

Aluminium foil + HCl 1 MEndothermic


54

Reaction Change occurZnSO4 + H2O

Chemical equations:

Analysis of data :


55

Conclusion :

TangSel, .................................. 20....

Assistant,

............................................


56

Purpose

Determine the reaction rate coefficient based on the formation of deposits.

Overview

Stoichiometry is a branch of chemistry that deals with the relative quantities of

reactants and products in chemical reactions. In a balanced chemical reaction, the

relations among quantities of reactants and products typically form a ratio of whole

numbers. For example, in a reaction that forms ammonia (NH3), exactly one molecule of

Nitrogen (N2) reacts with three molecules of Hydrogen (H2) to produce two molecules of

NH3:

N2 + 3H2 → 2NH3

Stoichiometry can be used to calculate quantities such as the amount of products (in

mass, moles, volume, etc.) that can be produced with given reactants and percent yield

(the percentage of the given reactant that is made into the product). Stoichiometry

calculations can predict how elements and components diluted in a standard solution

react in experimental conditions. Stoichiometry is founded on the law of conservation of

mass: the mass of the reactants equals the mass of the products.

Reaction stoichiometry describes the quantitative relationships among substances

as they participate in chemical reactions. In the example above, reaction stoichiometry

describes the 1:3:2 ratio of molecules of Nitrogen, Hydrogen, and Ammonia.


57

Composition stoichiometry describes the quantitative (mass) relationships among

elements in compounds. For example, composition stoichiometry describes the Nitrogen

to Hydrogen (mass) relationship in the compound Ammonia: i.e., one mole of Nitrogren

and three moles of Hydrogen are in every mole of Ammonia.

A stoichiometric amount or stoichiometric ratio of a reagent is the amount or

ratio where, assuming that the reaction proceeds to completion:

1. all reagent is consumed,

2. there is no shortfall of reagent, and

3. no residues remain.

A non-stoichiometric mixture, where reactions have gone to completion, will have only

the limiting reagent consumed completely.

While almost all reactions have integer-ratio stoichiometry in amount of matter

units (moles, number of particles), some non-stoichiometric compounds are known that

cannot be represented by a ratio of well-defined natural numbers. These materials

therefore violate the law of definite proportions that forms the basis of stoichiometry

along with the law of multiple proportions.


50 ml beaker glass, ruler, CuSO4 0,1 M, NaOH 0,1 M.

Procedures

1. Provide two 50 ml beaker. Into a beaker enter 5 ml of 0.1 M NaOH on the other

beaker insert 25 ml 0.1 M CuSO4 Combine the two solutions, then stir.

2. Allow the mixture a few moments until the precipitate formed at the bottom of the

beaker.

3. Measure the height of sediment formed using a ruler (use units of mm).

4. Perform the same manner as steps 1-3 for subsequent experiments by changing the

volume of each reagent but still 30 ml total volume, as follows:

10 ml of 0.1 M NaOH and 20 ml of 0.1 M CuSO4



58



5. Make a chart that states the relationship between the precipitate (Y-axis) and volume

of each solution (X-axis), so it make two curves on one graph.

6. From this graph determine the reaction coefficient based on the second cut point

curve. Cutoff state reaction coefficient comparison.

Analysis of data

In the experiment above, the graph obtained from the data between the high

deposition of the volume of each reagent is determined by changing the reaction

stoichiometry unit volume of each reagent having a mole intersection.

Moles = molarity x volume of solution

Thus obtained : mole ratio = ratio of the reaction coefficient

Questions

Pre-lab questions

1. Make it work steps in form of images on the lab journal

2. Write down all the equations in these experiments

Post-lab questions

1. Calculate the number of moles of sediment generated from each experiment

2. Sodium sulfate tetrahydrate of 240 g containing 162 g of water crystals. Molecular

formula is ....



59


Sketches of procedure Observation

Deposition reaction stoichiometry


60

Exp.- Volume of NaOH 0,1 M Volume of CuSO4 0,1 M Precipitate height12345

Reaction and calculations :

Analysis of Data :


61

Deposition reaction stoichiometry graphic

Conclusion :

Jakarta, ..............................., 20....Assistant

...............................................


62

Purposes

Colligative properties of solutions to experiment through trial decrease in

Harnstoff solution freezing point.

Overview

Colligative properties of solution is the physical nature of the solution only

depends on the number of solute particles and not depend on the type of solute. Are

classified as colligative properties of solutions are: decrease in vapor pressure, elevation

of boiling point, freezing point depression and osmotic pressure of the solution. In the

nature of the rise in boiling point and the colligative freezing point depression, the greater

the molality of the solution, the higher rise in boiling point of the solution and the higher

the decrease in freezing solution. Therefore, the solution increases the boiling point (Tb)

and a decrease in freezing solution (Tf), is directly proportional to the molality of the

solution. In the following experiments, will be tried as colligative properties of solution

freezing point depression.


Alat : 500 ml beaker glass 100 ml beaker glass Reaction tube Thermometer Stopwatch

Bahan : Harnstoff Ice cube Aquadest


63

Procedure

1. Enter as many as 50 ml of distilled water into a large test tube.

2. Enter the ice that has been crushed into a beaker approximately as high as the

solution in a test tube (so the ice can cover the entire solution in a test tube).

3. Insert the thermometer into a test tube containing distilled water. Record the

room temperature laboratory.

4. Prepare the stopwatch. Insert the tube into a beaker that has been filled ice cubes

at the same time and also run the stopwatch.

5. Observe the temperature changes that occur every 30 seconds. Do it to show a

constant temperature as much as three points.

6. Repeat steps 1-5 using a solution of harnstoff.

Analysis of data

From experiments on steps 1-5 for distilled water, make a graph of temperature

(Y-axis) with time (X-axis). Create a chart is also to step 6 (Harnstoff solution).

Pre-lab questions

1. What differentiates ordinary solution colligative properties colligative properties of

electrolyte solutions with?

2. What is the freezing point of 0.2 m Potassium bromide in water if it is known

freezing point of 0.1 m Sucrose solution in water is -0.18 º C.

Post-lab questions

1. In the experiment above, why ice cubes should cover the entire solution?

2. Make a comparison of the temperature drop of urea solution at a constant point

in the experiment with the urea solution freezing point of reference books

available.

3. What is the boiling point of Magnesium chloride solution of 0.05 m in water if it is

known boiling points of binary strong electrolyte is 0.25 m 100.26 º C.


64





65

Physical data of pure solvents and temperature measurement per 30 seconds

volumeTemperature and

room pressureMass (handbook) Corrected density

Solvent Mass

Times- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20T

Times- 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40T

Physical data and temperature measurement solution per 30 secondswater Harnstoff Mass Molality

Times - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20T

Times- 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40T

Physical data and temperature measurement solution per 30 secondswater Harnstoff Mass Molality

Times- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20T

Times- 21

22 23 24 25

26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

T

Calculations :


66

Analysis of Data :Graphic of temperature (Y-axis) with time (X-axis)


67

Conclusion :

TangSel, ................................... 20.....

Assistant,

............................................


68

Purpose

Understand the concept of equilibrium and the factors that influence it.

Calculate the equilibrium constant prices based on experiments.

Overview

Chemical reactions are generally in a state of equilibrium. Reaction in equilibrium

can be known from the macroscopic properties (such as color, concentration, etc.) that do

not change (at constant temperature) after reaching equilibrium conditions, but

symptoms did not change in the molecular two-way continuous. Macroscopic properties

are most easily observed, to determine the system has peak at equilibrium conditions or

not, is the change in color of the solution. For example, if we dissolve the I2 preformance

then the water will initially yellow solution which formed the longer the color of the

solution becomes darker and finally dark brown. The color of the solution will not change

anymore while the process of molecular (crystal dissolution I2) persists but offset by re-

crystal formation I2, therefore, after equilibrium is reached the number of crystals of I2 in

solution is always fixed.

This equilibrium condition can be influenced by several factors, including changes

in temperature, change of pressure and concentration changes. Where these changes can

lead to a shift in either direction toward reactant reaction and reaction products.


69

In a chemical equilibrium system temperature relationship as simple artifacts between

concentration of reaction products and reactants concentration. For the general reaction:

aA + bB → cC + dD

then the temperature remains valid: K=[ C ]c [ D ]d

[ A ]a [ B ]b , where K is the equilibrium constant.

Methode

At trial the determination of the equilibrium constant prices, will be studied reaction

Fe3+ + SCN- ↔ FeSCN2+ , where the concentration of each ion can be determined by

colorimetry. Determination in this way is based on the fact that the intensity of a beam of

light through a colored solution, depending on the number of colored particles that exist

in the path of the light beam. Thus the intensity of this light should be proportional to the

concentration of solution and the path length of light beam.

Color ≈ consentration (c) x height/width of solution chamber (d)

color = k x c x d ; k = constant

If we compare the kind of solution contained in two places (eg. tubes 1 and 2) the

same size but have different concentrations, then we can vary the amount of light beam

paths to the same color intensity resulting from the second solution. In this condition

applies:

K x c1 x d1 = K x c2 x d2

c1x d1 = c2 x d2


Apparatus : 100 ml beaker glass, 10 ml measuring cylinder, 10 ml volumetric pipet, Test tube, Bigger test tube, Pipet.Materials : KSCN 0,002 M; Fe(NO3)3 0,2 M; NaH2PO4 0,2 M.

Procedure

Ferri(III) thiocyanate


70

1. Enter 10 ml of 0.002 M KSCN into a beaker, then add 2 drops Fe(NO3)3 0,2 M,

then stir.

2. Divide the solution formed into 4 test tubes with an equal volume.

Tube 1 as control

Tube 2 add 10 drops KSCN 0,002 M

Tube 3 add 3 drops Fe(NO3)3 0,2 M

Tube 4 add 5 drops NaH2PO4 0,2 M

3. Observe and note the changes occur from that reaction.

Determination of equilibrium constant

1. Provide a 4 clean test tube (type and size of tube should be the same) and are

numbered 1 through 4.

2. Insert the 5 ml of 0.002 M KSCN into each tube.

3. Into the tube 1 add 5 ml Fe(NO3)3 0,2 M save it as a standard.

4. Into a 100 ml beaker, put 10 ml of Fe (NO3)3 0.2 M and add distilled water until the

volume of 25 ml (calculate the concentration of Fe3+). Pipette 5 ml of this solution

and put into tube 2. The remaining solution will be used for the next step.

5. Take 10 ml of Fe(NO3)3 of the rest of the experiment step 4, add distilled water until

the volume of 25 ml (calculate the concentration of Fe3+). Pipette 5 ml of this

solution and put into the tube 3. The remaining solution will be used for the next

step.

6. Do the same work as step 5 for the tube 4.

7. To calculate FeSCN2+ ion concentration, compare the color of the solution in tube 2

with tube 1 (as standard). Observations made by looking at the second color of the

solution from the top tube (observations appear above). If not the same color

intensity, remove the solution from the tube a drop by drop (in the capacity of the

other test tube to be reused) until the second solution in the tube shows the same

color. Measure the height of the two solutions with a ruler (in mm).


71

8. Do the same work as step 7 for the tubes 3 and 4 by comparing with the tube 1

(default).

Analysis of data

Calculations for each tube :

1. On the tube to-1 considered all the thiocyanate ion has reacted to FeSCN2+. The

solution in this tube is used as a standard.

2. Comparison of tube high = first tube height/tube height-n.

3. [FeSCN2+]equilibrate = comparison of tube height x [FeSCN2+]standard.

4. [Fe3+]equilibrate = [Fe3+]initial – [FeSCN2+]equilibrate .

5. [SCN-]equilibrate = [SCN-]initial – [SCN-]equilibrate .

6. Find a relationship that produces a constant value of the concentration of ions at

equilibrium for the tubes 2, 3, and 4 by the following calculation:

[Fe3+][FeSCN2+][SCN-]

[Fe3+][FeSCN2+]/[SCN-]

[FeSCN2+]/[SCN-][Fe3+]

Pre-lab questions

1. Sketch the step of procedure on lab journal.

2. Calculate the concentration of Fe3+ and SCN at first in units of molar

concentration of each reagent is inserted into the tubes 1, 2, 3 and 4.

Post-lab questions

1. From the calculation step to-6 Which combinations of a, b, or c indicating the

price constant or nearly constant? give an explanation.


72



Equilibrium of Ferri(III) thiocyanate



73

Determination of equilibrium constant values



74

Tube [Fe3+]initial [SCN-]initial d1 / dx[FeSCN2+]eq

A[SCN-]eq

B[Fe3+]eq

C1234

Tube A x B x C (A x B) / C A / (B x C)1234

Calculations and reaction equations :


75

Analysis of Data :


76

Conclusions :

TangSel, ...................................20.....

Assistant,


77

...............................

Overview

Colloidal system (hereinafter abbreviated as "colloidal" only) is a form of the

mixture dispersion system) two or more substances that are homogeneous but have a

dispersed particle size is quite large (100-100 nm), thus exposed to the Tyndall effect.

Means homogeneous dispersed particles is not affected by gravity or other forces applied

to him; so that no precipitation occurs, for example. Homogeneous nature is shared by the

solution, but not owned by usual mixture (suspension).

Colloids easily found everywhere: milk, gelatin, ink, shampoo, and clouds are

examples of colloids that can be found daily. Cytoplasm in the cells is also a colloidal

system. Colloidal chemistry were analyzed separately in the chemical industry because of

its importance.

Colloids have a variety of forms, depending on the phase dispersed dispersing

agents and substances. Several types of colloid:

Aerosols are having a gas dispersing agents. Aerosol has dispersed liquid substance

called liquid aerosols (eg, fog and clouds) while having a solid substance called

aerosols dispersed solids (eg, smoke and dust in the air).

Sol colloidal system of solid particles dispersed in liquid. (Example: The river, the

soles of soaps, detergents and sol ink).


78

Emulsion colloid system of liquid dispersed in another liquid, but the two liquids do

not dissolve each other. (Example: coconut milk, milk, mayonnaise, and fish oil).

Bubble Colloidal Systems of gas dispersed in liquid. (Example: on the processing of

metal ore, fire extinguishers, and other cosmetics).

Gel system of rigid colloidal or semi-solid and half liquid. (Example: agar-agar, glue).

Tyndall Effect

Tyndall effect is the phenomenon ray scattering (light) by the colloidal particles.

This is because the size of colloidal molecules are quite large. Tyndall effect was

discovered by John Tyndall (1820-1893), an English physicist. Therefore the nature of the

so-called Tyndall effect.

Tyndall effect is the effect that occurs if a solution is exposed to light. At the true

solution is irradiated with light, then the solution will not scatter light, whereas in colloidal

systems, the light will be scattered. it happens because the particles are colloidal particles

having a relatively large to scatter light. Conversely, the true solution, the particles are

relatively small so that scattering occurs only a few and very difficult to observe.

Brownian motion

Brownian motion is the movement of colloidal particles that always move straight

but erratic (random motion / irregular). If we observe under the microscope ultra colloid,

then we will see that the particles will move to form a zigzag. Zigzag movement is called

Brownian motion. The particles of a substance in constant motion. These movements can

be random as in liquids and gases (called motion brown), whereas in solids only

beroszillasi in place (not including the motion of brown). For colloids with medium

dispersing liquid or gas, the movement of particles will produce collisions with the

colloidal particles themselves. The collision took place from all directions. Therefore the

particle size small enough, then the collisions that occur tend to be balanced. So there is a

resultant collision that causes change in direction of motion of particles resulting in a

zigzag motion or Brownian motion.


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Materials and apparatus :

Materials : FeCl3; aquadest; agar-agar, gelatine, kerosene, protein flour, instant yeast,

sugar, milk powder, butter, salt, sulfur powder, detergent.

Apparatus : 100 ml beaker glass, alcohol burner, tripod, gauze, stir rod, analytical balance,

spatula, mortal and pestle, test tube, oven, pan.

Procedure :

A. Preparation of Colloids by condensation

1. Preparation of sol Fe (OH)3

Heat 50 ml of distilled water in a 100 ml beaker until boiling.

Add 25 drops of saturated solution of FeCl3 and stir until the mixture while

continuing warming red brown.

B. Dispersion Method

1. Preparation of sulfur sol

Mix one gram of sulfur and sugar that is refined.

Take the mixture and add one gram of sugar and Crush until smooth.

Continue the work to four times.

Put some final mixture into a glass cup containing 50 mL of distilled water and stir.

Observe.

2. Preparation of agar gel

Fill a test tube with distilled water until the third.

Add gelatin and stir, heat to boiling tube.

Refrigerate the mix until it became gelatinous.

3. Makers of oil in water emulsion

Put about 5 ml of water and 1 ml of kerosene into a test tube.

Shake the tube, and save it on the tube rack, observe what happens.

Put about 5 ml of water, 1 mL of kerosene and 1 mL of detergent solution in

another tube.

Shake the tube, and store in a tube rack, observe that occurred.


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4. How to make white bread:

Enter the high protein flour, instant yeast, sugar, and milk powder, stirring

until blended.

Add water little by little and stir until the dough is rather dull.

Add the white butter and salt, continue stirring until dough is dull.

Round the dough and rest for 10 minutes.

Divide the dough @ 450 grams and let stand for 15 minutes.

Formed bread dough and place it in the bread pan was smeared with

margarine.

Let the dough (+ 90 minutes). Bake until cooked, brownish yellow (for

temperature = 200 oC baked for 20 minutes).

Question

1. Write the reaction that occurs in the manufacture of soles Fe(OH)3 !

2. Explain the differences in the manufacture of colloids by means of condensation

and dispersion !.

3. What substances are formed after burning gel Ca-Acetate ?


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82


83


84

Reaction equations :

Analysis of data :


85

Conclusion :

TangSel, .................................20....

Assistant,


86

.......................................

FORMAT PEMBUATAN LAPORAN PRAKTIKUM

COVER LAPORAN :

LAPORAN PRAKTIKUM

KIMIA DASAR I

( JUDUL PERCOBAAN )

( Tanggal Praktikum )

Disusun oleh :

(Nama Praktikan)

(NIM)

Kelompok : xx

1. xx(nama teman sekelompok)

2. xxxxxxxxxxxxxx

3. xxxxxxxxxxxxxx

PROGRAM STUDI PENDIDIKAN KIMIA

JURUSAN PENDIDIKAN ILMU PENGETAHUAN ALAM


87

FAKULTAS ILMU TARBIYAH DAN KEGURUAN

UNIVERSITAS ISLAM NEGERI SYARIF HIDAYATULLAH

(Tahun)

SISTEMATIKA LAPORAN :

1. Judul percobaan

2. Tujuan percobaan

3. Pendahuluan/dasar teori

4. Alat dan bahan

5. Sketsa prosedur kerja dan pengamatan

Sketsa prosedur kerja Pengamatan

6. Perhitungan dan persamaan reaksi

7. Analisis data

8. Pembahasan

9. Kesimpulan


88

10. Daftar pustaka (min. referensi dari tiga buku kimia tingkat universitas

dan satu dari website/blog)


general chemistry chemistry

Technology

chemistry experiments

means of experiments

results of experiments

authorchemistry experiments

laboratory officer

xxobservation data sheet

trash bagchemistry experiments

laboratory coat