CHEMISTRY DEMOS, LABS,

AND PROJECTSNSTA-Atlanta 2012

Nancy BrimLakeside High School

Atlanta, Georgia

Nancy_H_Brim@fc.deKalb.k12.ga.ushttp://fc.dekalb.k12.ga.us/~Nancy_H_Brim/Conferences

ELEMENTS, COMPOUNDS, MIXTURES, AND SOLUTIONS

Differences

ELEMENT COMPOUND SOLUTION MIXTURE

Similarities

ELEMENT and COMPOUND SOLUTION and MIXTURE

COMPOUND and SOLUTION

DENSITY COLUMNEXTRA CREDIT

You are to construct a density column using an approximately 500 mL plastic (no glass) soda bottle or some other type of plastic container. You must have a minimum of FIVE layers, with extra, extra credit being given for additional layers. Each layer must be neatly labeled on the bottle itself next to each layer. Your name and period should also be on the bottle.

This project will involve a great deal of experimentation where you will need to mix different substances to see which ones will not dissolve in one another, and which will float on top of one another. It is a good idea to use food coloring to make some of the layers more visible.

Some Safety Precautions: 1. Do not use ammonia, bleach, or anything that contains ammonia or bleach. Toxic fumes may be

produced. 2. Always read the labels of all substances you try and follow necessary safety precautions.3. Do not use any flammable substances (like lighter fluid, gasoline, paint thinner) as many of these react

with plastics. 4. Try to stick with things you drink or cook with. Try to avoid cleaning substances (see #1).5. If you mix two things in your bottle and they begin reacting, as evidenced by fumes being given off or

bubbles being produced, DO NOT PUT THE CAP BACK ON! Take it outside immediately until the reaction ceases.

Prizes will be awarded for the bottle with the most layers that are clearly visible and for the most colorful bottles. Good Luck!

DENSITY DEMO

Materials: fish tank, water, variety of canned drinks

I start out with Coke, Diet Coke, and Caffeine Free Coke. Have a discussion about which the students think will sink and which will float.

Put cans in water (be sure to put them in sideways so that air will not catch in the bottom of the can). Coke will sink, Diet Coke will float, Caffeine Free Coke floats.

Challenge your students to bring in other drinks – Sprite, Coke Zero, etc.If the cans are left in overnight, they all float - brings up an interesting discussion.

PLAYING BINGOStudents are told to pull out one of their nomenclature worksheets. They are to put the written name or formula in each of the bingo boxes. I have a particular handout that I use and I have cut the names/formulas into strips. I have cut up a bunch of pieces of colored paper as markers. They can use any resource that they can use on the test (periodic table and/or ion names). The students cover the flask with a marker. When I call out a name/formula, it is the answer to the written one the students wrote down. Students must learn to hear a formula and find the name and vice versa. We play until someone gets five in a row and then keep playing (no

       

         

       

       

         

Name _____________________________ Period _____ Date __________________

A Roll of the Die

Purpose:To practice writing names and formulas of compounds

Materials: Bag of ion die paper writing utensil

Procedure: 1. Open the bag of dice and separate the anions from the cations.2. Picking up one anion die and one cation die, roll them on a hard surface.3. In the table below, write the ions as they appear, then write the formula and the name of the compound.4. Repeat steps 2 and 3 with the same two dice four more times. If you get the same set of ions again, re-roll.5. Put those two dice aside and pick up another anion die and another cation die. Roll them on a hard surface,

write their ions, formula, and name. Do this four more times with those dice.6. Put those two dice aside and pick up another anion die and another cation die. Roll them on a hard surface,

write their ions, formula, and name. Do this four more times with those dice.7. Pick up a remaining anion die and the cation die with Cu+2 on it. Roll them on a hard surface; write their ions,

formula, and name. Do this four more times with those dice.8. Pick up the last anion die and the cation die with Al+3 on it. Roll them on a hard surface; write their ions,

formula, and name. Do this four more times with those dice.

Data

CATION ANION FORMULA NAME

OFF TO THE RACES

Introduction: If a little is good, more is better right? Increasing the mass of a reactant in a chemical reaction may not increase the amount of product that can be formed – the yield may be limited based on the mole ratio of the reactants. You will see for yourself the concept of limiting and excess reactants by comparing the amount of carbon dioxide obtained when varying amounts of sodium bicarbonate react with a constant amount of acetic acid.

Safety: Acetic acid is a skin and eye irritant. Avoid contact with eyes and skin. Wear goggles.

Materials: 2M Acetic acid NaHCO3 (solid) 6 balloons6 125mL Erlenmeyer flasks funnel scoopula10mL graduated cylinder weigh boats electronic balance

Procedure:1. The teacher will assign you a flask and a number, 1-6.2. To your flask add 10.0mL 2M acetic acid.3. Measure out the assigned amount of NaHCO3 into your weigh boat using the electronic balance. See

Table One for all amounts.

TABLE ONE

SAMPLE Mass NaHCO3

1 0.50g2 1.00g3 1.50g4 2.00g5 2.50g6 3.00g

4. Obtain a balloon for your flask. Stretch the balloon and blow it up at least once. Then let as much air out of it as possible.

5. Use the funnel to add your sample of NaHCO3 to the balloon.6. Carefully attach the balloon over the mouth of the flask. Don’t let any NaHCO3 into the acetic acid

yet.7. Make a prediction as to what will happen when the NaHCO3 is added to the acetic acid in all six

flasks. How will the size of the inflated balloons vary when the reactions are complete? (Write your answer below IN INK!)

Largest: __________________________________________________:Smallest8. When your teacher says so, all students will lift their balloons and shake them so that the NaHCO3

falls into the acetic acid. Make sure the neck of the balloon stays firmly attached to the flask.9. The reaction is immediate and vigorous. Allow the reaction to proceed until all the bubbling stops. 10. Compare the size of the inflated balloons and whether the solid is all gone in each case. Rank the

balloons below:

Largest: __________________________________________________:Smallest

Calculations:Your goal is to calculate the theoretical number of moles of gas produced in EACH reaction. You have

two reactants to work with - Sample grams #1-6 NaHCO3 and 10.0 mL HC2H3O2. You will then identify the limiting reactant and the excess reactant in each case. The balanced equation is:

NaHCO3 (s) + HC2H3O2 (aq) NaC2H3O2 (aq) + CO2 (g) + H2O (l)

1. Calculate the number of moles of CO2 produced for each mass sample of NaHCO3. Be sure to show all work, units, and significant figures. Put a box around your answer for each sample calculated. Put this on a separate piece of paper please.

2. Calculate the number of moles of acetic acid used. Then calculate the theoretical mass of CO2 produced. Your teacher will do this with you. Put this on a separate piece of paper please.

3. Once you have the answers to #1 and #2, fill in the table below:

Sample Moles of CO2

produced by NaHCO3

Moles of CO2

produced by HC2H3O2

Moles of CO2

theoretically produced

Limiting Reagent

Excess Reagent

4. Discuss what you learned about this reaction using the calculations above and your knowledge of limiting reactants.

5. How did the relative sizes of the balloons compare to your answers of theoretically produced CO2?

Activity – Electron Configuration BattleshipSummary

Students practice electron configuration – standard notations – using the “Battleship” game format. Students may play one-on-one or in teams of two. Students claim this activity is both fun and a very effective method of practicing electron configuration. Time frame: 30 minutes or more.

Chemistry Concepts: electron configuration – standard notations (and noble gas if option is played)

Materials

Game rules overhead transparency periodic tables – laminated and in foldersVis-à-vis markers

Procedure Notes

The general format of the game “Battleship” involves placing ships on a grid hidden from the opponent’s view. The opponent “fires” at your ships by naming grid coordinates (e.g. B3). You respond by stating whether the shot was a “hit” or a “miss.” Likewise, you fire at your opponent’s ships. All shots are recorded by placing pegs in the game board (red for a “hit,” white for a “miss”). A ship is “sunk” when all available spots on the ship have been hit. Whoever sinks all of his opponent’s ships first is the winner.

The primary modification in this game is the firing method. Instead of naming grid coordinates, students must give the electron configuration of the targeted element. To make sure both students are in agreement, the opponent confirms the targeted element by saying its name. If both students agree, the electron configuration was most likely stated correctly. Students are only allowed to use aids that will be available on tests.

Individual vs. Team Play: This game is most appropriate for individual play. However, if a student was absent when the material was presented, pairing him with a knowledgeable student is an ideal way for him to catch on.

Periodic Tables: These are laminated and stapled to folders. Each person gets one folder. Unfold the folders “laptop” style and attach back to back with a paperclip so they stand up.

Markers: Vis-à-vis markers are used since the periodic tables are laminated.

Another Option:

Material addition: poker chips, dice, etc. (to provide a random selection between 2 choices)

Poker chips/Dice: These are used by the students to randomly select between the standard notation or noble gas notation so that both methods can be practiced. Any number of alternatives could be used instead of poker chips. Additional Directions:

Player #1 draws a chip and “fires” at an element by giving the appropriate electron configuration. red chip – standard notation blue chip – noble gas notation

Teacher Notes

Electron Configuration BattleshipMaterials (per group of two)

2 laminated periodic table folders2 different colored markers

Game Rules1. Each player uses a marker to draw one ship per sublevel. Each ship should be arranged

vertically or horizontally and should occupy the specified number of boxes. s-sublevel – Destroyer – p-sublevel – Cruiser – d-sublevel – Battleship –

2. Players now switch colored markers3. Player #1 “fires” at an element by giving the appropriate electron configuration (not the

shorthand one).4. Player #2 confirms the targeted element by saying its name and declares it a “hit” or “miss.”5. Player #1 records the “hit” with an “X” or “miss” with an “O” using colored marker.6. Players trade roles.7. The player who sinks all of his or her opponent’s ships first is the winner!

NUT and BOLT STOICHIOMETRY

1. Give each group a bag of nuts, bolts, and washers. 2. Show them a set (one nut, one bolt, and one washer)3. Have them put together as many sets as they can.4. One the board, record the nuts, bolts, washers, and sets for each group.5. Discuss limiting reactant, excess reactant.

DEMO OF THREE BOND TYPES

Materials: two plastic/tennis balls (need to be hollow balls) thin rope

Have two students come up to the front of the class. Have them face each other. Each student holds a ball, representing an electron. The other end of the rope is held by the other student. Each student should be holding a ball in one hand and the other end of the rope is attached to his partner’s ball in the other hand.

IONIC: One student wear a piece of paper that reads Cl EN = 3.0. The other wears one that says Na EN = 0.9. Ask the class to predict the positions of the electrons. The electron belonging to Na should be transferred almost completely to the Cl atom. The Cl should move a little towards the Na. This shows that no bond is 100% ionic.POLAR COVALENT: use CO. Two cards are C EN = 2.5 and O EN = 3.5. The electrons are closer to the o than the C, but approaching the center of the two atoms. This shows unequal sharing.NONPOLAR COVALENT: Use H2. Two cards are H EN = 2.1. The electrons therefore will be in the exact center of the ropes since each is equally attracted to the other’s nucleus.

Transparency Directions

GLOW IN THE DARK STARS

Materials: package of glowing stars, laser pointer, flashlight, UV light, three books/magazines

1. Place a glowing star in each of three books/magazines the day before you use them so there is no stored light.2. Give one student the laser pointer, one the flashlight, and one the UV light. 3. Give necessary safety precautions about the lights.4. Turn the lights off and have the students hold their light source on the stars for 30 seconds. 5. At the end of 30 seconds, turn off the light and close the book.6. Next, have the students check to see if their stars are glowing.DATA

1. laser light - 670 nm wavelength stars glow? ____________________________2. flashlight - 500 nm wavelength stars glow? ____________________________3. ultraviolet light - 254 nm wavelength stars glow? ____________________________4. glowing star light - 520 nm wavelength

CALCULATIONSA. Convert wavelength in nm to meters.

Example: Convert wavelength in nm to meters.Laser: (670nm) (1.00 x 10-9m/1 nm) = 6.70 x 10-7m

B. Using Planck’s energy formula and the speed of light formula, determine the energy for each. Calculating Frequency υ = c ÷ λ Laser: υ = c ÷ λ = (3.00 x 108m/s) ÷ (6.70 x 10-7m) = 4.48 X 1014 HzCalculating Energy E = h υ Laser: E = h υ = (6.626 x 10-34 Js)(4.48 X 1014 Hz) = 2.97 x 10-19J

CONCLUSION1. Would infrared light cause the stars to phosphoresce?2. Would microwave light cause the star to phosphoresce?3. Give another example of minimum energy photons.

NATURE OF LIGHT

Materials: three LED lights (red, green, blue) Write and See Square

1. Move the red light on the yellow vinyl square and look for a trail of green glowing pigment.2. Move the green light on the yellow vinyl square and look for a trail of green glowing pigment.3. Move the blue light on the yellow vinyl square and look for a trail of green glowing pigment.

Blue will leave a trail because it has enough energy to excite the phosphorescent pigment. The excited pigment then slowly releases the energy as green light. Red and green light to not have enough energy to affect the pigment. Therefore, the Write and See Square has a minimum energy requirement that is not met by red or green light. (Write and See Square and LED lights from www.teachersource.com)

Our eyes have a minimum energy requirement of approximately 750 nm or 4.00 x 10-11Hz (red light).

ELEMENT PROJECTChemistry Assignment

Mrs. Brim

For this assignment, you will be creating a 6” x 6” tile about an element that is assigned to you. You will also submit requested information about the element separately.

Your element is:

Use your textbook and resources from the library to locate information about your element. Refer to this for the information you need to include on both the tile and the info sheet. Set up your tile and information sheet in the format described here. The assignment is worth two lab grades, so include all the required information and do your best!!! Your tile should be fun to look at. After all is may make the wall!

The assignment is due ____________________________

THE TILEUsing a plain WHITE sheet of paper – no lines – create a 6” x 6” square for your element. You should ONLY include the four following items:• the element name • the element symbol • atomic number• color picture/drawing/something depicting something about your element*On the back of the paper write your name and the year in pencil at the edge (so it does not bleed through).

THE INFORMATION SHEETOn the backside of this paper, fill in the information requested.• the number of protons in this element• the number of neutrons in the isotope as found on

the class periodic table• the number of electrons in this element• the atomic number• the mass number• the atomic mass • its natural state (solid, liquid, gas)• the family/group (column) it belongs to in the

periodic table (number and name)• its classification (metal, non-metal, metalloid)• Write the electron configuration, orbital diagram,

and electron dot for the atom indicated above.Be sure to have units for the next five items.• its melting point °C• its boiling point °C• atomic radii (in calculated picometers)• first ionization energy (KJ/mol)• electronegativity (in paulings)• electron affinity (high or low)• who discovered the element • when it was discovered• how it was named (where the name came from)

• some of its characteristics (such as color, odor, whether it is dangerous - explosive, toxic, radioactive)

• Any interesting facts about the element (is it found in the body, what is it used to make, what are its uses?..., etc.)

BONUS: Draw the electron configuration and orbital diagram for an excited state of this element.

=============================================================================Cite all the sources you used for this project using the MLA style. You must have at least three sources and they cannot all be websites. Attach a Works Cited page to this sheet when you turn in the information.

Name ________________________________________ Period _____ Date ______________________

ELEMENT NAME _________________________________ SYMBOL: __________See the other side for an explanation of each of the items on this page.

• protons

• neutrons

• electrons

• atomic number

• mass number

• atomic mass

• natural state

• family name

• group number

• its classification

• electron configuration

• orbital diagram

• electron dot diagram

===============================================================================Be sure to have units for the following.• its melting point °C

• its boiling point °C

• atomic radii (calculated pm)

• first ionization energy (KJ/mol)

• electronegativity (paulings)

• electron affinity• discoverer

===============================================================================

• when discovered

• how it was named

• characteristics (three or more)

• interesting facts

BONUS: Draw the electron configuration and orbital diagram for an excited state of this element.

DRAWING THE THREE PHASES OF MATTER

Have the students get out a piece of paper before talking about the phases of matter. Have them draw three boxes like the ones below. Tell them to imagine they are looking through a microscope and could see individual atoms in each container (box). What would the atoms of the solid look like? The liquid? The gas? I tell them they should use 24 balls to represent 24 atoms in each container.

SOLID LIQUID GASWhen reviewing their drawings, look for the following misconceptions:

1. Gravity does not matter in the container.2. Solid and liquid atoms are not similar in their spacing.3. Gas and liquid atoms are not free to fill their container.

THREE PHASES OF MATTER DEMOSMolecular Motion:

Materials: 3 tennis balls, clear tennis ball can, gallon size Ziploc bagSOLID: Put the balls in the can with the lid on and shake the can. This shows molecules/atoms moving/vibrating around a fixed point, unable to break away.LIQUID: Pour the tennis balls into the Ziploc bag and close it. Move the bag around showing that the molecules/atoms touch each, have more freedom of movement, but do not break apart.GAS: Get a student to juggle the three balls. Even if he/she drops the balls, they stay in the “container” (classroom).

Compressibility:Materials: 3 syringe with end caps, Georgia red clay, water, air

SOLID: Put 4cm3 of Georgia red clay into syringe and cap.LIQUID: Put 5mL of water into syringe and cap.GAS: Put 7 mL of air into syringe and cap.Give each to a student. Ask the student to notice the starting volume and then push on the plunger as hard at they can. Determine the new volume.

THE BIG CHILLINSULATION PROJECT

Problem: Which substances offer the best insulation from heat transfer by conduction, convection, or radiation?

Materials: fiberglass insulation, wood, Styrofoam, cardboard, etc. (Just suggestions, you are the final decision-maker on the structure.)

1. Design and build a container for a “pet” ice cube. 2. The container cannot be bigger than 15cm on any side. 3. The container must have an opening to accommodate an

ice cube – see photo. 4. All containers must be original creations. (In other words,

Tupperware and Thermos products, or any other manufactured products are not allowed.)

5. The final project must operate at room temperature without electricity.6. We will not work on this in class at all.7. Once you give the project to me on the due date, you may not touch it again until you

get your grade for it days later.

Grading: You may work by yourself or in a team of two (you and one other person). Each member of the team must participate fully in the project. There will be no free rides. Don’t choose someone who is not going to work! The container will be graded as follows:

Construction – built neatly by hand (25 pts), completed on time (10pts), all sides no more than 15cm long (5 pts each side)

Efficiency – based on life span of ice cube. < 2hr (25pts), 2-3.5 hr (35 pts), 3.5-4.5 hrs (40 pts), 4.5-5.0 hrs (45 pts), >5 hrs (50 pts)

There will be bonus points for being one of the top three finishers in your class, for ice cubes lasting longer then 8 hrs, for best design, and for parent signature on form.

DUE DATE: Competition Date:

Members of group: ____________________________ ________________________________(print) you your partner, if any

Materials Used in Project:

Parent Signature ______________________________________ Date ____________________This signature adds five points to your grade!!

Names _____________________________________ Period _____ Date _________________________

____________________________________

PLAYING WITH BALLOONS AND CANS

We are beginning the section on the Gas Laws. These are laws that deal with how pressure, temperature and volume are interrelated when used with gases.

For each of the activities, do the following. I am looking for a thoughtful analysis of each situation, using the gas laws as a basis around which to form your intelligent well-reasoned responses.

1. Record all observations in paragraph form. Please make detailed observations, above and beyond what is specifically asked for.

2. For the conclusion for each experiment, explain why you observed what you did. If you can determine a relationship between temperature and pressure, temperature and volume, or volume and pressure, say what that relationship is. If a gas law applies, give the name of the law and how it applies. Do not just state the definition of the law, but rather state how this law specifically applies to each situation.

You will turn in one lab for each lab group. This sheet should be on top with the answers in chronological order attached. No title page is required. Each member in the group should initial which responses they answered.

WEAR GOGGLES FOR THESE1. Too Hot to Touch: Pour about 25 mL of water into a soda can. Fill the white bucket half full of water and add one cup of ice.

Place can on a ring stand with an iron ring and wire gauze and heat to boiling. After steam has been rising out of the can for several minutes, firmly grasp the can with the beaker tongs. Quickly invert the can (open end down) and submerge into the bucket of ice water. Make observations of what happened while heating and once the can is placed in the bucket.

2. An Utterly Deflating Event: Place about 10mL of very hot water (get from the back desk) in a large test tube and attach a balloon to the test tube. Heat the water to boiling (don’t melt the balloon!). Make observations. Quickly plunge the test tube into a beaker of ice water. Make observations.

YOU CAN TAKE YOUR GOGGLES OFF IF THE PEOPLE ACROSS FROM YOU ARE ALSO FINISHED WITH #1 AND #2.3. Up, Up, and Away: Blow up a balloon all the way. Feel the surface of the balloon and note the temperature of the balloon.

Make observations. Deflate the balloon and note its temperature. Make observations.

4. Can You Pull Enough? Fill a clean cup with water. Take a sip of water with the straw. Make observations. Using scissors, cut out a small piece of the straw above the water surface. Then drink out of the straw again and make observations.

5. From a Stream to a Trickle: Fill a two liter bottle with water, keeping a finger over the hole at the base. Inflate a balloon and attach to the top of the bottle. Remove your finger from the hole holding the bottle over the sink. Make observations. Remove the balloon. Fill the bottle again with water, attach a deflated balloon, and remove your finger from the hole while holding the bottle over the sink. Make observations.

PRESSURE DEMO

Pressure is force per unit area - like N/m2

Materials: square meter of cloth 2 pkgs Fig Newtons spring scale1. 6 fig newtons = 1 N

show this by placing 6 Fig Newtons in a plastic bag and hanging it from the spring scale.

2. 1 N/m2 - Spread the 6 Fig Newtons out on the cloth NOT MUCH FORCE3. 1 Kpa = 6000 Fig Newtons/m2

put the 60 Fig Newtons (in a bag on the cloth and tell them the force is 10x this.4. 101.3 Kpa = 608000 Fig Newtons

This is atmospheric pressure – what is pushing down on you right now.FYI: 600,000 Fig Newtons (if laid on top of each other) would be 29 feet high!

GIANT SYRINGE

Acquire a giant horse syringe (http://www.flinnsci.com)Make sure your syringe has a leur loc cap or a similar way to close off the tip.Place a large marshmallow in the syringe and push it down to the bottom with your finger.Place cap on syringe tip.Pull back plunger and watch marshmallow grow in size.Example of Boyle's Law - lower pressure and volume increases.

Extension: Place room temperature tap water in syringe. Place cap on syringe tip.Pull back plunger slowly and let it go back. Then pull the plunger back and allow it to snap back. This creates seed air bubbles throughout the water. Pull back the plunger one more time and boiling happens in these seed bubbles.

GIANT TUBES OF SCIENCEBuy the long 8 foot covers for fluorescent light bulbs. Cap one end and fill so it seals. I used heavy duty glue and duct tape.

You can run several demos with this:1. Fill the tube ¾ full with 0.1M NaOH and universal. Place in a bucket to help with overflow.

Add several pieces of dry ice and watch the colors change.2. Fill tube ¾ full with 0.1M HCl and enough Universal to get the red color. Add 1.0M Na2CO3

gradually to the tube. Color variations of the rainbow should appear. Na2CO3 sinks, neutralizes the HCl. At various depths, the [H+]varies, producing layers of varying pH.

INSTANT CARNATIONSBuy three or four silk flowers. Soak each one in a different indicator. Squirt them with ammonia water to show the base color. Over time, they will return to their original color as the ammonia evaporates. I used phenolphthalein and universal indicators.

FINDING ACIDSSoak a light colored sponge in Congo Red indicator. The sponge will turn red. As students are doing a lab with acids, walk by and wipe the sponge across any spill on the counter. Acid spills will turn the sponge a dark blue/black. This drives home the need to clean up all spills immediately.

Name ___________________________________________ Period _____ Date____________________

FIRST DAY STATIONS

Station A Syllabus - Pick up the two pages of the syllabus. Read through it, sign it, and answer the following questions. Be sure to get your parents to sign it tonight.1. How many points do you lose for late work EACH day? 2. List three things you should have everyday for class.3. How much is the project that coincides with the periodic table worth?4. Do we study the orbital configuration of neutral atoms this semester?

If so, what standard is it?

Station B Textbook - Select a text book and a textbook form. Fill out the form using the laminated example. Put your name AND my name in your textbook on the inside cover. Answer the following questions. Bring the form and textbook to your teacher.1. How much does it cost to replace your textbook?2. What chapter is about the Mole?3. Define DENSITY and give the page number where you found it.4. Who was Dmitri Mendeleev and give the page number where you found it.

Station C Continuation Form - Pick up a Continuation Form, read it, and get it signed by your parents. Due Wednesday.

Station D Student Information Form - Pick up a Student Information Record. Please fill out the top portion, through “Tell me about yourself and your family”. Flip over to the back and fill out the “Interest Inventory”. Any information that you do NOT know should be filled in tonight at home and returned to me tomorrow.

Station E Homework - Write down the following quote from Henri Poincaré. This is your homework and it is due tomorrow. In at least two paragraphs (and at least ten sentences), write a response to it. I do not want to know Webster’s or Google’s definition of science, I want to know what YOU think.

“Science is built of facts that way a house is built of bricks; but an accumulation of facts is no more science than a pile of bricks is a house.”

- Henri Poincaré

Station F Seating Chart - Find the seating chart for your period and fill in your name in the appropriate seat box in PENCIL. Be sure to fill in named called and last name. Also, put your called name and last name on a popsicle stick on place the stick in the BRIM can.

Station G Fortune Teller Fish – Pick up a Fortune Teller fish and follow the package instructions. Play with it for a minute and try to get it to curl in various ways. Why do you think it moves in your hand? Find a partner and try to figure out why it moves. Come up with a testable question for tomorrow.

FORTUNE TELLER FISH ACTIVITIES:Day One: Do the First Day Stations and give each student a Fortune teller Fish. Have them explore with the fish.Day Two: Ask how the fortune teller fish works. Discuss possible solutions. Model steps of the scientific method. Have

students pair up (or work alone) to write up a n experiment to determine the cause of the “curling fish”. Be sure to include a hypothesis, material list, and experimental procedure. Submit before the end of the period for approval. Teacher acts as a facilitator and guide to help the writing of the experiments.

Day Three: Perform experiments, revise as necessary, write a simple data table, analyze, and draw a conclusion. Lab report is due at the end of the week. Teacher provides requested materials, acts as a facilitator and guide to help the performing of the experiment and writing of lab report.

QUALITATIVE ANALYSIS OF HOUSEHOLD CHEMICALS

Years ago, the American Chemical Society offered a prize to anyone who could find a substance that was not a chemical. The point, of course, was that all matter, whether “artificial” or “natural,” is composed of atoms and molecules. Although most students readily accept this truism, they often view the chemicals they work with in the laboratory as something different from the materials that abound in the “real world.” This experiment, in which the ‘active ingredient” in many household products will be identified, is an attempt to bridge the gap between the chemistry lab and the household environment.

You will be provided with a number of white solids, identified only by an alphabetical code. Your job will be to identify each of these unknowns correctly. The possibilities are table salt, sugar, Epsom salt, alum, photographic fixer, corn starch, aquarium sand, chalk, baking soda, and washing soda. Many of these materials are likely to be found in the typical home. Others, while not as common, are readily available in pharmacies, building supply stores, or camera shops, and may be purchased without a special license or prescription.

Suggestions for identifying the unknowns using chemical tests are made below. Note that many of the test reagents are themselves in products commonly used in the home. For instance, anthocyanin is an extract from red cabbage. It acts as an acid-base indicator in the pH range of 3-10. Acetic acid (HC2H3O2) is a weak acid, with a characteristic sour taste; vinegar is essentially a 1 M solution of acetic acid. Ammonia is usually in a gaseous form; its aqueous solutions are alkaline and are commonly used as household cleaners. Pure iodine is a solid that sublimes at slightly elevated temperatures. Alcoholic solutions of iodine (tinctures of iodine) are often used as disinfectants.

The information given below should enable you to devise a plan for identifying the unknowns. The formulas given are those of the main ingredient in each household item (of course, the materials used in the home are generally not pure and there is no single formula for the complete mixture.)

Solubility in WaterChalk, (main ingredient: CaCO3, calcium carbonate), cornstarch (main ingredient: a polymer of glucose

(C6H10O5), and aquarium sand (main ingredient: SiO2, silicon dioxide) are insoluble in water. Epsom salt (main ingredient: MgSO4 7H2O, magnesium sulfate heptahydrate) dissolves with a noticeable cooling effect.

Reaction with AmmoniaAddition of aqueous ammonia to a solution of Epsom salt produces “milk of magnesia”, a suspension of

magnesium hydroxide that has a milky appearance.Alum (main ingredient: NH4Al(SO4)2 5H2O, ammonium aluminum sulfate pentahydrate) is used as an

astringent and as a pickling agent. Addition of aqueous ammonia to a solution of alum produces a gelatinous precipitate of aluminum hydroxide. The other water-soluble unknowns do not react with ammonia.

Reaction with Acetic AcidLike all carbonates, chalk will fizz when treated when acid. Washing soda (main ingredient: Na2CO3,

sodium carbonate) and baking soda (main ingredient: NaHCO3, sodium hydrogen carbonate or sodium bicarbonate) will fizz when treated with acetic acid.

Reaction with IodinePhotographic fixer (main ingredient: Na2S2O3 . 5H2O, sodium thiosulfate pentahydrate) is soluble in

water and is capable of reducing I2 molecules to I- ions. It will decolorize brown iodine solutions and also remove the blue color of the iodine-starch complex. Starch will turn blue when treated with iodine.

Reaction with AnthocyaninRed cabbage juice is a natural indicator that works in a pH range of 3-10. Washing soda turns a

yellowish/green, baking soda turns blue, and table salt, sugar (sucrose, C12H22O11), photographic fixer, and Epsom salts turn violet.

Conductivity of ElectricityTable salt (main ingredient NaCl, sodium chloride), like Epsom salt, alum, fixer, washing soda, and

baking soda, produces ions when dissolved in water. Thus, solutions of table salt will conduct electricity.

PROCEDUREDevise a scheme for separating unknowns into groups and then identifying the members of each group.

You should base your procedure on the groups discussed before this. No matter where you start, you will find it helpful to follow the suggestions given below.

1. In determining solubility, use only a pea-sized (or smaller – like the size of an earring stud) quantity of solid placed in a test tube. Add roughly 10 mL of water and mix well. You need just enough solid to be easily seen if it does not dissolve but not enough to form a saturated solution if it is moderately soluble. A slight cloudiness may be due to a trace of insoluble filler and should not lead to a conclusion of “insoluble” if major portions of the sample dissolves.

2. To determine if an unknown will fizz when treated with acid, place a pea-sized quantity of solid in a test tube and add a few drops of acetic acid.

3. When testing materials with anthocyanin, ammonia, or iodine, dissolve the unknown in water and add only two or three drops of reagent.

4. Remember that reagents may interfere with one another. For instance, if you have several solutions and add iodine to each, all of the solutions, except the one containing the photographic fixer, will turn brown. Adding anthocyanin (in an effort to determine pH) would then be futile; the brown color would mask any other colors that might develop. Use fresh samples whenever it seems necessary.

5. To test for conductivity, use your 100mL beaker. Add a pea-sized amount of solid and 10-20mL of deionized water (no tap water). When using the conductivity tester, make sure that you have dipped the prongs in water and wiped them off. Be sure to clean the prongs between each test. ONLY THE PRONGS GET WET – NOTHING GREEN SHOULD GET WET!!!!!

6. Do not add anything to the containers of unknowns or test reagents. Do not move spatulas from one container to another. DO NOT CONTAMINATE!!!!

Writing Your Lab Report

When writing up this lab report, please include the following sections:

Title pageSafety precautions

Materials (all that you used)Procedure (tests for each unknown performed)

Data (observations noted)Conclusion (state the name and formula of each unknown

and reason why it is correct)

For example, after writing the title page, start a new page with the safety precautions and materials. One way to write the report would be to then have a section for each unknown. State the letter of the unknown chemical, the tests performed and the observations noted. That is technically the procedure and data section together. Then in your conclusion, list each unknown’s letter, formula, and what chemical you determined it to be, and reasons for your choice. When writing the tests performed, there is no need to write out the step by step for the test unless it is one that was not listed for you above. Just say something like “Chemicals A-J were tested for solubility in water”. I would like to know the order in which the tests were done.

Or, you can write each procedure and tell on which compound(s) it was performed. Then have a data section where you list your observations for each. Either way, make it easy to read and follow...

This is an individual lab report and your conclusions should be based on your own scientific judgment, not that of others. You will be working with your partner at your lab desk, but drawing your own conclusions. As a result, you and your lab partner can draw different conclusions based on the same data.

Follow all the instructions for writing regular lab reports - a copy is posted in the classroom if you have forgotten. Remember to use only third person.

This lab report is due on ____________________

LEGIBILITY IS VERY IMPORTANT !!(If I cannot read it, I will not grade it!)

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HOUSEHOLD CHEMICALS LABGRADING RUBRIC

Getting the Correct Answer - 25%

9-10 correct 25 pts 5-6 correct 14 pts7-8 correct 19 pts <5 correct 10 pts

Lab Report - 50%

Title page - 5 pts if all parts are evident, 3 pts is information is missing, 0 pt if missing

Safety - 5 pts if sufficient safety rules are listed, 3 pts for a partial list, 0 pts if section missing

Materials - 5 pts if all materials are listed, 3 pts for a partial list, 0 pts if section missing

Procedure - 10 pts for all procedures listed or explained, 5 pts for a partial list, 0 pts if missing

Data, Observations, Analysis - 20 pts if all data, observations and analyses are listed and I follow your deductive reasoning; 13 pts if most of the data and analyses are there, 6 pts if most of the data and analyses are missing, 0 pts if missing entirely

Conclusion - 10 pts for all chemicals identified with formula and reason , 7 pts for two of three parts, 4 pts for one of three parts, 0 pts if missing)

Classification - 25 %

Performed tests - 15 pts if all tests were performed on all chemicals, 10 points if some tests were performed, 5 pts if very few tests were performed, and 0 pts if no tests were performed

Presented Data - 10 pts if data is presented in an organized and logical way, 5 pts if the data is somewhat confusing, 0 pts if data makes no sense at all