UNIT 4 – Solutions and Solubility

Chapter 8 Solutions and Concentration

Types of Solutions

The simplest solutions contain 2 substances:

1. SOLVENT

o

o

2. SOLUTE

o

When solute dissolves in a solvent, ________________________________ and the

substances can be ________________________________________________________.

Solutions are ______________________ mixtures and can be _____________________.

Steel –

Kool-aid –

Air –

Most common solutions are _________________

The most common of these are _________________________ where ___________ is the

_______________________

Many substances dissolve easily ___________________________. These substances are

said to be ___________________ with each other.

Ex.

Some substances _______________ dissolve in each other. These are said to be

___________________________. Ex.

SOLUBILITY is a measurement of __________________________________________

____________________________________________________________________.

Ex. The solubility of NaCl in H2O at ___________________________________.

A ________________________________ SOLUTION is a solution that

________________________________. If we try to add ______________________ of

NaCl to 100mL of H2O, it will ______________________________

An __________________________ SOLUTION is a solution ____________________.

Solutes described as _________________ have a solubility of _____________________

Solutes described as _________________ have a solubility of _____________________

Solutes described as __________________________________ have a solubility of

____________________________________________________

Factors Affecting Rate of Dissolving and Solubility

The ____________________________________________ measures how fast a

______________________________________. This rate is dependent on many factors.

1. _____________________

a.

b.

2. ____________________

a.

3. _______________________

a.

b.

The reason that one substance dissolves in another is because of ____________________

________________________________________________________________________

The forces include the attraction between:

1.

2.

3.

When the force of attraction between _______________________ particles is

____________________________ the attraction between ______________ particles a

_______________________ is formed.

The ____________________________________ between particles determines solubility

Recall the Thought Lab on pg. 288:

Iodine was insoluble in water. This means that the ______________________________

____________________________________________________. Also the force of

attraction between ________________________ (intermolecular forces) are strong.

Iodine was soluble in kerosene. The force of attraction between ___________________

____________________________________ than the attraction between

_________________________ as well as between ______________________________.

INTERMOLECULAR FORCES

In Unit 1 you learned the difference between polar and non-polar molecules.

Recall water:

Water is polar because it appears to other molecules to have _______________

______________________________________. Molecules like this are said to have a

______________________________________.

A DIPOLE consists of ____________________________________________________.

Remember how water “sticks” to water?

This is a result of the ______________________________________________________.

These are called __________________________________________________________.

This is a type of _________________________________________. They act between

molecules. These forces are about ______________________ as an ionic or covalent

bond (______________________________)

A special type of dipole-dipole attraction happens when __________________________

_____________________________________. Because these atoms are so

____________________________________, H gets a positive charge that is

_________________________. This leads to __________________________________.

When ________________ substance are dissolved in a ______________________ the

the _____________________________ of the ionic compound are attracted to different

___________________________. This is known as _____________________________.

In an _______________________ each cation and anion will be surrounded by _______

___________________. Each ion is said to be ___________________ and

________________________ can move freely in the solution making it an

____________________________________ (soln with the ability to conduct electricity).

__________ ionic compounds are soluble but _________________.

To predict solubility __________________________________:

Large difference – __________________________________________________

Small difference – __________________________________________________

When _______________________________ are mixed with water, most are _________.

This is because many are _________________________. Exceptions are

______________ and _______________. Both of these form ______________ with

water.

However, ______________ covalent compounds are soluble in _____________ solvents.

In general ____________________________________________.

- _____________________________ solutes dissolve in _______________ solvents.

- ___________________ solutes dissolve in ______________________ solvents.

Some substances behave as both polar and non-polar substances. _______________ is

an example

Factors Affecting Solubility

Don’t get confused with ________________________________________.

1. Molecule Size

- .

-

2. Temperature

-

- When a solid dissolves ________________ to break bonds between particles.

-

- This is true for __________________.

- For ___________ energy is not required so temp has ________________ on

solubility

- When ____________ dissolve in liquids they actually lose energy, so

__________________________________________________________________

3. Pressure

- Changes in pressure have __________________ on solid and liquid solubility

- The solubility of a gas is __________________________________________

______________________________________________________________

- For example in a 2L pop bottle the pressure of CO2 is ___________________.

Solubility of CO2 in the ____________________. When you open the bottle,

the pressure of CO2 ________________________________, solubility

______________________________________________________________!

Concentration of Solutions

Mass/Volume Percent

Chemists often express the concentration of an _____________________________ as

the MASS ____________________________________________________________.

It is usually expressed as a _________________________________

It can also be referred to as __________________________________

This is different from solubility. (mass per unit volume)

Ex 1. A pharmacist adds 4.0 mL of H2O to 8.00g of powdered drug. The final volume

of the solution is 6.00mL. What is the percent (m/v) of the solution? What is the

concentration in g/100mL?

Ex 2. Trisodium phosphate (TSP) is used as a cleaner to prep surfaces before painting.

The recommended concentration of TSP is 1.7% (m/v). What mass of TSP is required to

make 4.0L of solution?

Mass / Mass Percent

The __________ of a solution containing a solid solute dissolved in a liquid solvent can

be expressed as the _________________________ and is called

________________________________________ (you might also see it as w/w percent)

Many metal alloys have their concentration expressed as

percent (m/m)

Ex1. Dental amalgam used as dental fillings is made by mixing mercury, silver and tin.

If a sample of a dental filling has a mass of 1.35g and after heating the solution you

obtain 0.4725g of silver, what is the mass/mass percent of silver in dental amalgam and

how much would you need to make 100g of dental amalgam?

Volume / Volume Percent

When mixing 2 liquids it is common to express _______________________________.

This may also be referred to as ______________________________________________

Ex 1. Rubbing alcohol is an antiseptic. It is sold as 70% (v/v). What volume of

isopropyl alcohol is used to make a 500ml bottle?

Parts per million and Parts per billion

____________________________ are usually used to express

_______________________ in the )___________________________________. Both

are usually mass/mass relationships.

For (ppb) substitute 106 with 10

9

Ex1. A toxic fungus that grows on peanuts can cause liver damage in humans. The

maximum amount of toxin allowed is 25ppb. If 20t of peanuts are to be made into peanut

butter, what is the maximum mass of toxin permitted?

Ex 2. Mercury is toxic in humans if more than 20mg has accumulated.

i.Express this in ppm for a 75kg person

ii.Express this in ppb

iii.Express this in (m/m) percent

Molar Concentration

This is the concentration used in chemistry

____________________________ is the ______________________________________

Molar [ ] can be referred to as ________________________

This formula can be shortened to:

Units are ___________________________

The advantage of using molar concentrations is that it is related to the # of particles in the

solution. None of the other concentrations are.

Ex1. A saline solution contains 0.90g of solute dissolved in 100mL of solution. What is

the molar concentration?

Ex 2. Formalin is a solution containing formaldehyde, CH2O, used to preserve biological

specimens. What mass of CH2O is required to prepare 2.25L of 10.5M solution?

Preparing Solutions

A soln of known concentration is referred to as a _______________________________.

There are 2 ways to make a standard solution:

1.

2.

To prepare a standard solution you use a ___________________________________.

These flasks are able to measure to _______________________

Diluting a Solution

You can also make a less concentrated standard solution by adding a measured amount of

extra solvent to a solution with a known concentration.

Ex. 1 You must make 2.0L of 0.10M sulfuric acid. This acid is sold as 18M. How much

of the standard solution do you need to make the new solution?

There is an easier way. ____________________________________________________

_______________________________________________________________________

_______________________________________________________________________

This formula can be used to solve basic dilution questions.

Try the above question again.

Chapter 9 Aqueous Solutions

Making Predictions about solubility

Recall:

Soluble Partly of Slightly Soluble Insoluble

Factors that affect the solubility of Ionic Substances

1. _________________________

Ions with small _______________________________________________.

Ions with large ________________________________________________.

Increasing the charge _____________________________________________.

For example: ________________ tend to be insoluble, __________ salts soluble.

2. _____________________________

Compounds with __________________________________________ than

compounds with __________________________.

___________________ ions ____________ more closely than ______________.

The above can allow you to make some predictions about solubility. What do think about

sulfides (compounds with S2-

)?

There are many interrelated factors affecting solubility, and _____________________

must be _____________________________________________________ for solubility.

Chemists rely on published data to determine ________ a substance is soluble,

____________ soluble it is, and it’s _______________________ to other similar

compounds.

There are however ________________________________________________________.

Guideline Cation

Anion Result Exceptions

1

2

3

4

5

To use this table remember that ______________________________________________

________________________________________________________________________

Reactions in Aqueous Solutions

When you mix 2 aqueous ionic compounds together 2 things can happen:

1.

2.

If a chemical reaction occurs you may observe:

1.

2.

3.

1.___________________

To predict the formation of a __________________________________, use your

_______________________________________________________________ and your

knowledge of _________________________________________ to predict the out come.

Ex. Will the following reaction produce a precipitate?

Pb(NO3)2 + KI

2. _________________________________________

Double displacement reactions can result in the production of the following

________________________________________________________________________

__________________ Gas

- ________________ (alkali metal + H) react with water to produce

_______________.

_____________ Gas

- ________________ react with certain acids to produce ____________.

_____________ Gas

- Some reactions produce a product that ____________________________.

_____________ Gas

- __________________________ to produce carbonic acid, which

decomposes into _______________________________.

__________________ gas

- _____________________ react with bases to produce _____________.

3. _____________________

Neutralization reactions between __________________________,

____________________ and acids, and ________________________ and bases all

result in the formation of water.

IONIC EQUATIONS

Imagine mixing aqueous solutions of NaCl and AgNO3.

You would predict that:

The other ions are not really important to the overall result.

We call these ions _______________________________.

The chemical equation for this reaction is:

This reactions shows the reactants and products as _________________________. In

reality though the compounds ______________________________so chemists usually

refer to the _________________________________________________________.

Now you can see the _____________________________. Because they appear on

_______________________________________________________________________.

This is called the ______________________________________.

Copy the guidelines for writing Net Ionic Equations from pg. 342.

Ex. 1 Aqueous solutions of sodium sulphide and iron (III) sulphate are mixed. Identify

the spectator ions and write the balanced net ionic equation.

Stoichiometry in Solution Chemistry

These problems are solved the same way as the previous stoichiometry problems you did

with the addition of a couple of items:

1.

2.

Ex. 1 Calculate the [chloride ions] in mol/L the following solutions:

a. 19.8g of potassium chloride dissolved in 100mL of solution.

b. 26.5g of calcium chloride in 150mL of solution

c. a mixture of the two solutions in a. and b. assuming the volumes are

additive.

Ex 2. Rhubarb leaves are poisonous because of the oxalate C2O42-

ions present in them.

If you tested 238.6 g of leaves by adding calcium chloride to precipitate calcium oxalate

and extracted 0.556g of calcium oxalate, what was the mass percent of oxalate ions in the

leaves?

Ex. 3 Solutions containing silver ions are often mixed with chloride ions to precipitate

silver chloride. What is the minimum volume of 0.25mol/L magnesium chloride needed

to precipitate all the silver ions in 60mL of 0.30 mol/L silver nitrate?

Ex 4. When Hg is used in industry it must be removed from all waste water, because it is

toxic. Suppose 50.00mL of 0.045mol/L sodium sulphide is added to 101.4mL of 0.05M

mercury (II) nitrate. What mass of mercury (II) sulphide precipitates?

Ex 5. Silver chromate Ag2CrO4 is insoluble. Calculate the mass of silver chromate that

forms when 50.0mL of 0.25M silver nitrate reacts with 25.0mL of 0.30M sodium

chromate.

Chapter 10

Acids and Bases

Acids and bases are common products.

Citrus Fruits

Dairy products

Soft drinks

Underarm odour

Oven cleaner

Baking Soda

Glass Cleaner

Acids and bases are groups of chemicals that share similar physical and or chemical

properties

Properties Acid Bases

Taste

Indicators

Feel

Form ions in solution

Conduct electricity

React with metal

React with carbonates

Theories of Acids and Bases

Since their discovery, people have tried to describe what makes an acid an acid and a

base a base.

Arrhenius Theory of Acids and Bases

In the late 19th

century the Swedish chemist named Svanté Arrhenius discovered that

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

Arrhenius published his theory:

- ____________________________________________________________

____________________________________________________________

- ____________________________________________________________

____________________________________________________________

According to Arrhenius’ theory, acids (which always contain an H+ ion) _____________

_______________________________ and bases (which always contain an OH- ion)

_________________________________________________________.

Arrhenius theory is useful if you are interested in ________________________________

________________________________________________________________________

However there are some problems:

1. The ion responsible for making an acid is H+. This happens when acids are added

to water. But what happens between ___________________________________?

In the 20th

century, chemists discovered that H+

ions

_____________________________________ but are always ______________.

A hydrated H+ ion is called a __________________________________________

2. Consider the base NH3. _____________________________________________

_________________________________________________________________.

3. It is limited to acid-base reactions _________________________.

Brønsted-Lowry Theory of Acids and Bases

In 1923 two chemists (independently) came up with a new theory, which helped explain

the limitations of the Arrhenius theory.

There theory stated:

- ____________________________________________________________

- ____________________________________________________________

Brønsted-Lowry acids also contain an _____________. This means all ______________

________________________________________________________________________

But, ___________________________________________________________________.

According to Brønsted-Lowry theory there is only one requirement for an acid-base

reaction:

________________________________________________________________________

________________________________________________________________________

This means that any substance can be an acid as long as __________________________

_______________________________________________________________________.

The reverse is true as well.

Consider HCl added to water

Two molecules or ions that are related by the transfer of a proton (H+) are called a

___________________________________________________________________

The ________________________________ of an acid is the particle that remains when a

proton ______________________ from the acid.

The ________________________________ of a base is the particle that results when the

base _________________________ the proton from the acid.

Ex1. Hydrogen bromide is a gas that is soluble in water. The resulting solution is called

hydrobromic acid. Identify the conjugate acid-base pairs.

Ex.2 Ammonia is soluble in water. It forms a basic solution commonly used in window

cleaners. Identify the conjugate acid-base pairs in the reaction between ammonia and

water.

Ex 3. Identify the conjugate acid-base pairs as well as the acid, base and conjugate acid

and base.

HCOOH + CN- HCOO

- + HCN

Strong and Weak Acids and Bases

ACIDS

In a STRONG ACID the acid _______________________________________________.

HCl is a strong acid. All the HCl molecules ____________________________________

________________________________________________________________________

________________________________________________________________________

Strong acids include:

In a WEAK ACID the acid _________________________________________________.

On average about 1%

________________________________________________________________________

________________________________________________________________________

Most acids are weak.

Acetic Acid is an example of a weak acid

The arrows mean this reaction is ____________________. Molecules of acetic acid

dissociate just as _________________________________________________________

to produce acetic acid molecules.

Mono, Di, Tri – Protic Acids

Some acids contain only a ____________________________ that can dissociate. These

are called _________________________________.

Many acids contain _______________________. These are referred to as

_______________________. Sulphuric acid is an example

The first dissociation is complete. The remaining hydrogen sulphate ion is a __________

________________________________________________________________________

Some acids are _____________________________________________.

The more dissociations that take place ________________________________________.

Bases

Strong and weak bases follow the same rules as the acids above.

Strong Bases

Naming Acids and Their Anions

There are 2 kinds of acids: Binary Acids and Oxoacids (oxyacids).

Binary Acids are composed of 2 elements: ______________________________.

They have the general formula HX

To name:

1.

2.

3.

4.

Oxoacids are formed from a ____________________ that contains _________________

______________________________________________________

To name:

1.

2.

3.

pH

pH stands for the “power of hydrogen”.

Think about water. All aqueous solutions contain ions, even pure water.

On average at 25oC on 2 water molecules in a billion are dissociated at any time. Since

ions in solution are required to conduct electricity, pure water is not a conductor.

In neutral water the [H3O+] at 25

oC is 1.0x10

-7 mol/L

Therefore the [OH-] is also 1.0x10

-7 mol/L

Compared with neutral water acidic solutions contain [] of hydronium ions. Basic

solutions contain [] of hydronium.

The pH scale – Powers of 10

Concentrations of hydronium ions ranges from about

_______________________________________________________________________.

The big range and negative powers of 10 are not convenient to work with.

The Danish biochemist Søren Sørensen came up with a method to measure [ ] using a

logarithmic scale.

The logarithm of a number is the power to which you must raise ____________________

________________________________________________________________________

Sørensen defined pH as ___________________________________________________

So water has a pH of

Ex 1. Orange Juice has a [hydronium ions] of 2.5x10-4

. What is the pH of orange juice?

Ex 2. Household ammonia has a pH of 11.9. What is the concentration of [H3O+]?

Neutralization Reactions

There are many types of acids and bases and being able to predict the results of reactions

between them is important.

The reaction between _____________________________________________________.

SALT is an ______________________________________________________________

For example sodium nitrate is used to slow the rate of bacterial growth in foods. It can be

made by mixing nitric acid with sodium hydroxide.

The balanced chemical equations shows:

-

-

For most neutralization reactions there is ______________________________ that a

reaction is occurring. To see this we use ______________________________________.

Most indicators are _____________________________________________, where the

the _____________________________________ is one colour and its

_______________________________ a different colour.

Phenolphthalein is an example_______________________________________________

Calculations involving Neutralization Reactions

Ex 1. You have 25.00mL of NaOH left over from your experiment and you want to

neutralize it before dumping it in the sink. You find that it takes 19.75mL of HCl to

neutralize it. What was the [ HCl ]?

Ex. 2 What volume of 0.50M sulfuric acid is needed to react completely with 45mL of

0.85M calcium hydroxide?

In a titration experiment, 25.00mL of an aqueous solution of NaOH was required to

neutralize 55.00mL of 0.010M HCl. What was the molar concentration of NaOH?

Read pg. 399 to 401 and make your own note on ACID-BASE TITRATION.