Imagine a hot
summer day.
You’ve been
outdoors and you
are really thirsty.
A tall, cool glass
of water would
taste great.
Or would it?
Have you ever tasted distilled
water from the supermarket?
It tastes flat.
 It is “just plain water”
 To make it you boil tap water so it
becomes a gas. Then you collect the liquid
 It separates the water from the dissolved
materials that give it flavor.

Tap water
A mixture of pure water H2O and
a variety of other substances,
such as chlorine, fluoride, and
metallic ions. Gases like carbon
dioxide are also dissolved in
water.
Tap water is an example of a kind
of mixture called a solution.
Acids, Bases, and Solutions
Suspension
A mixture in which particles can be seen
easily and separated by filtration or
settling.
 Pepper and water make a suspension

Solutions
 Homogeneous
mixtures (well mixed) in
which parts are too small to be seen and
do not settle.
 Same properties throughout
 Can not be separated through filtering or
settling. May use evaporation or boiling
away.
 Salt water is an example.
ALL Solutions
 Consist
of 2 parts:
 Solvent: does the dissolving, present in
largest amount.
 Solute: is dissolved, present in smaller
amount.
Examples of Solutions
Soda is a solution of
carbon dioxide,
sugar,
and flavorings
dissolved
in water.
An alloy is a solid
solution of metals.
Water as a Solvent
 In
many common solutions, the solvent is
water.
 Sugar in water, for example, is the starting
solution for flavored soft drinks. Adding
food coloring gives the drink its color.
Dissolving carbon dioxide gas in the
mixture produces soda.
 Because water dissolves in so many
substances it is often called the
“UNIVERSAL SOLVENT”
Solutions Without Water
 Many
solutions are made with solvents
other than water


Gasoline is a solution of several different
liquid fuels. (C8H18)
SOLUTIONS can be made of any combination
of gases, liquids, or solids.
Have you ever put a packet of
powdered flavoring into a bottle
of water?
 What
happened to the powder?
Particles in a solution
 Why
do solutes seem to disappear when
you mix them with water?
 If you had a microscope powerful enough
to look at the particles in the mixture what
would you see?
This is what happens!
 Whenever
a solution forms, particles of the
solute leave each other and become
surrounded by the particles of the solvent.
Conductivity and Solutions
 Many
ionic compounds are highly soluble
and dissolve easily in water.
 Water molecules attract the ions and pull
them away from each other.
 The solution that forms when an ionic
compound dissolves in water can conduct
an electrical current.
 Happens because the ions are charged
and can move freely past each other.
http://www.stevespanglerscienc
e.com/content/sciencevideo/pickle-electricity-
Concentration
Suppose you make two cups of tea. You leave the first tea bag in the cup
For 15 minutes. You put a second tea bag in a second cup for only a few
minutes. When you are done, one cup of tea is darker than the other.
What is happening?
They differ in their
concentrations
 They
differ in the amount of solute (tea)
dissolved in a certain amount of solvent
(water).
 Dilute solution: A small amount of solute is
dissolved in the solvent.
 Concentrated solution: A mixture that has
a lot of solute dissolved in it.
Solubility
 Solubility:
A measure of how well a solute
can dissolve at a given temperature.
If a substance dissolves in
water then, how well does it
dissolve?”
 Suppose
you add sugar to a glass of ice
tea. How much can you add?
 You can add half a teaspoon to make it
sweet.
 Or, you can add two teaspoons to make it
really sweet.
 IS THERE A LIMIT TO HOW “SWEET” IT
CAN BE???????
YES!!!!
 At
the temperature of ice tea, three or four
tea spoons are about all you can add.
 No matter how much you stir the tea, no
more sugar will dissolve.
Saturated, unsaturated, or
supersaturated?
solutions hold the maximum
amount of solute at a given temperature

solutions are not holding as
much as possible at that temperature

solutions are holding
more than they should be able to at the
given temperature.

What increases the rate of
solution?
 Crushing
the
solute
 Heating the
solvent, if you
are dissolving a
solid in a liquid
 Stirring the
solution
Which holds more solute?
 Warm
liquid holds less dissolved gas
 Warm liquid holds more dissolved solid
This solution is saturated. It is holding all it can,
and we can see some undisolved solute.
Changing Solubility
 Which
holds more sugar: iced tea or hot
tea?
• Ice tea quickly becomes saturated
• Yet, hot tea can hold several more teaspoons of
sugar!
FACTORS AFFECTING
SOLUBILITY
 Temperature:


Solids: as temperature is increased, solubility
increases
Gases: Become less soluble when temp goes
up.


More carbon dioxide will dissolve in cold water than in
hot water. If you open a warm bottle of soda, carbon
dioxide escapes the liquid in greater amounts than if the
water had been chilled.
Why does warm soda taste “FLAT”? Because it contains
less gas!
Solubility in 100 g water at 0
degrees C
COMPOUND
SOLUBILITY (g)
SALT NaCl
35.7
Baking Soda NaHCO3
6.9
Carbon Dioxide CO2
0.348
Sugar C12H22O11
180
Soda instantly freezes!
 http://www.stevespanglerscience.com/cont
ent/experiment/instant-freeze-soda-ice
Next Factor
 Solvents:




Have you ever shaken a bottle of salad
dressing? Then you have seen how quickly
water and oil separate.
Why? Water is polar and oil is nonpolar.
Polar and nonpolar compounds do not mix
well.
Liquids: The solvent affects how well a solute
dissolves.
LIKE DISSOLVES LIKE
 Ionic
and polar compounds dissolve in
polar solvents.
 Nonpolar compounds do not dissolve in
polar solvents
• Example- Paints


Latex or water based paints can be cleaned up with just
soap and water
Oil-based paints require cleanup with a nonpolar solvent,
like turpentine.
Effects of solutes on solutions
 Making
ice cream!!!

First we mixed the milk, sugar and vanilla.
Then we froze the mixture by using ice.
To make it cold enough what did we add?

SALT!!! Why?


 Milk
freezes at a temperature lower than
the freezing point of water (0 degrees C)
 Adding salt to the ice created a mixture
that was several degrees cooler, cold
enough to freeze the ice cream!!
Salt can affect boiling point too!
 Have
you ever added salt to a pot of water
when you were trying to cook spaghetti?
 Why?



Water boils at a temperature higher than
100 degrees C, the boiling point of water.
Adding two teaspoons of salt/ quart will raise
the boiling point 1 degree C.
This change is enough to cook the spaghetti
faster!
Effects of solutes on Solutions
 Lowering
freezing point: Solutes lower the
freezing point of a solvent.
• Salt was the solute added to water when we made
ice cream.
 Higher
boiling points: Solutes raise the
boiling point of a solvent.
• Salt added to water when boiling spaghetti
ACIDS AND BASES
Acid and Bases Magic
Click above for website link
Acids and Bases
Acids and bases are substances
with specific physical and
chemical properties
We can determine if substances
are acidic or basic by testing their
pH or by indicators.
What did you eat for breakfast
today?
An apple? An orange? Fruit juice?
If so, an acid was part of your meal.
What is an Acid?
Acids: Any compound that increases the
number of hydronium ions, when dissolved
in water.
A substance that tastes sour, reacts with metals
and carbonates, and turns litmus paper red.

Hydronium ions form when a hydrogen ion,
H+, separates from an acid and bonds with a
water molecule, H2O, to form a Hydronium
ion H3O+
WHAT ARE SOME
EXAMPLES OF ACIDS
THAT YOU KNOW??
Properties of Acids
Sour Taste
Ever tasted a lemon?
What did it taste like? Other foods like
this?
Contain citric acid
Other fruits like cherries, tomato, and
apples also contain acid
Vinegar a solution of water and acetic acid
NOTE: Chemists never taste chemicals in
order to identify them. Even though acidic
foods are safe to eat, chemicals in labs
may not be!!
Acids change color in indicators
Turns blue litmus paper red
Bromthymol turns from blue to yellow
Destroy chemical properties of
bases
This is called neutralization
They cancel each other out
Conduct an electrical current
A water solution of the given substance
will conduct an electric current.


Acids break apart in water and form ions
Ions make it possible to conduct an electrical
current!
React with metals
Upon chemically reacting with an active metal, will produce
hydrogen gas (H2).
The key word, of course, is active. Some metals, like gold, silver or
platinum, are rather unreactive and it takes rather extreme
conditions to get these "unreactive" metals to react.
Not so with the metals in this property. They include the alkali metals
(Group I, Li to Rb), the alkaline earth metals (Group II, Be to Ra), as
well as zinc and aluminum.
Just bring the acid and the metal together
at anything close to room temperature and
you get a reaction
Indicators
Organic substances that
change color in the presence
of an acid or a base.
Red cabbage juice will
change color in the presence
of acids or bases
More properties of acids
Contain hydrogen
Ionize in water to produce positive
hydronium ions (H3o+)
React with active metals
May be hazardous
Proton donors
USES OF ACIDS
Used in many areas of industry and in
homes.
Citric acid & ascorbic acid (vitamin C)= are found in
orange juice. Help give soda its sharp taste
Hydrochloric acid= make metals from their ores.
Separates metals from the materials in which they are
combined.
Nitric acid= fertilizer, rubber and plastic
Sulfuric acid= most widely used industrial chemical in the
world
 Paper, paint, detergent, fertilizer
Common Acids
BASE
Any compound that increases the
number of hydroxide ions, OH+,
when dissolved in water.
Properties of Bases
Taste Bitter
Have you ever accidentally tasted soap?
Then you have tasted a base.

NOTE: Never use taste a way to identify a
substance that is an unknown chemical, this
can be very dangerous.
Slippery feeling
Soap also has that slippery feeling.
Why?


They dissolve the fatty acids and oils from your skin and this cuts
down on the friction between your fingers as you rub them
together.
In essence, the base is making soap out of you. Yes, bases are
involved in the production of soap! In the early years of soap
making, the soaps were very harsh on the skin and clothes due
to the high base content. Even today, people with very sensitive
skin must sometimes use a non-soap based product for bathing.
Bases change color in
indicators
Change the color of litmus paper blue
Bromthymol blue turns blue in the
presence of a base.
Destroy chemical properties of
acids
This is called neutralization
They cancel each other out
Conduct an electrical current
Why?


Increase the number of hydroxide ions, OH-,
in a solution.
This ion is a hydrogen atom and an oxygen
atom bonded together. This gives they
hydroxide ion a negative charge.
USES OF BASES
Soap and paper
Oven cleaners
Products to unclog drains
Compounds used to make cement and
plaster
Household cleaners and fertilizers
Antacids
More properties of bases
Contain hydroxide ion (OH-)
Proton acceptors
Can be poisonous and corrosive
Common bases
pH Scale
pH = a value that is used to express the
acidity or bascity (alkalinity) of a system
Describes how acidic or basic a solution
is.
Measure of the hydronium ion
concentration in the solution
How to read the pH scale
Scale ranges from 0-14
7 is neutral, solution is neither acidic or
basic (pure water)
Acids solutions have pH less than 7
Bases have pH greater than 7
Neutralization reaction
The reaction of an acid and a base to form
a neutral solution of water and a salt.


Salt= an ionic compound that forms when a
metal atom replaces the hydrogen atom of an
acid.
Uses = many industrial and home uses
Season food, preserve food, make other
compounds (lye, sodium hydroxide and baking
soda)
REMEMBER THE ICE CREAM LAB???

Decrease the freezing point of water
Neutralization
Acid + Base = Water + Salt
Ex: HCl + NaOH  H2O + NaCl
pH < 7
Turn
litmus
from
blue to
red
ACIDS
Change phenolphtalein to colorless
BASES
pH > 7
Turn
litmus
from
red to
blue
Change phenolphtalein to pink
It’s time for lab!