Section 8.3
Solutions Can Be Acidic, Basic, or
Neutral
Acids and Bases Have distinct
Properties
• Items containing acids
– Orange juice
– Tomatoes
– Vinegar
• Items containing bases
– Soap
– Ammonia
– antacids
A-B. Acids, Bases, and Their
2. Chart to
Characteristics
Acid
Base
Proton
donates
accepts
Taste
sour
bitter
Sensation
burning or
prickling
slippery;can
burn as bad
as an acid
React with
carbonates & fatty acids to
most metals make soap
Turns Litmus red
blue
compare
and
contrast
acids and
bases
Definition of Acid
A substance that can donate a proton
to another substance and has a pH
below 7.
Definition of a Base
A substance that can accept a proton
from another substance and has a pH
above 7
Definition of pH
• The concentration of hydrogen ions in a
solution; a measurement of acidity
Definition of Neutral
• Describing a solution
that is neither an acid
nor a base and has a
pH of 7
II. The strengths of acids and
bases can be measured
3. What makes an acid
or a base strong?
• A stong acid or base
breaks apart
completely into ions
What makes an acid or a
base weak?
• A weak acid or base
does not form many
ions.
4. Chart with Examples of strong
and weak acids and bases
Strong
Weak
Acid
Hydrochloric
Acid
Acetic acid
Base
Sodium
hydroxide
Ammonia
A. Acid and Base Strength
5. What is the difference • A large percentage of
between a strong acid
the strong acid or base
or base and a weak
breaks down into ions
acid or base?
in solution
• A low percentage of a
weak acid or base
breaks down into ions
in solution
B. Measuring Acidity
6. pH
•
•
•
•
Scale to measure H+ concentration
High pH means low H+ ion concentration
Low pH means a high H+ ion concentration
Usually ranges from 0 to 14
6. Neutral
• Not acid; not base
• Pure water is neutral
• H+concentration equals OH- concentration
III Acids and bases neutralize
each other.
• How does an antacid
tablet relieve an upset
stomach?
– Stomach acid has a pH
of about 1.5. An
antacid tablet contains
a base that reacts with
excess acid. A salt and
water are produced,
and the pH level in the
stomach increases and
is returned to normal.
Examples of Neutralization
Reactions
• 3HCl + Al(OH)3  AlCl3 + 3H2O
Acid Base
salt
water
• H2SO4 + 2KOH  K2SO4 + 2 H2O
Acid
Base
salt
water