Chapter 9 Section 3:
Acids and Bases
Acids (pg. 250)
1. Acids = substances that contain hydrogen & produce
hydronium ions (H3O+)when they dissolve in water
1. Acids dissolve in water & release positively charged
hydrogen (H+) ions which then combine with H2O &
produce H30+
Properties of Acidic Solutions
(pg. 250 – 251)
1. Sour taste, but never use taste 2 determine acids or bases
2. They conduct electricity b/c they contain ions
3. They R corrosive as well
4. Some acids react w/ metals 2 produce metallic
compounds & hydrogen gas
5. Carbonic acid is formed from carbon dioxide dissolving in
water
6. Stalactites & stalagmites R created b/c of the carbonic
acid which dissolves the limestone rock
Uses of Acids (pg. 251 – 252)
1. Vinegar contains acetic acid
2. Lemons & oranges contain ascorbic acid (vitamin C)
3. Formic acid comes from ant stings
4. Batteries contain acids b/c of the electric current it conducts
5. Sulfuric acid is used is fertilizers, steel, paint, & plastics
6. Hydrochloric acid is used to remove dirt & stains from metals
& brick walls
7. Nitric acid is used in fertilizer, dyes, plastics, & explosives
Bases (pg. 252)
1. Bases = substances that produce hydroxide ions (OH)when they dissolve in water
2. Properties: slippery, bitter taste
3. Bases R corrosive
4. They also contain ions  conduct electricity
5. Usually do not react w/ metals
Uses of Bases (pg. 252 –
253)
1. Hydroxide ions strongly react w/ dirt & grease, which
is why soaps & cleaning products R bases
2. Ammonia is in fertilizers, fibers, and plastics
3. Antacids, chalk, & oven cleaners also contain bases
4. Blood is a basic solution
5. Calcium hydroxide is a base (called lime) often used 2
mark lines in fields & found in paving materials,
plaster
pH (pg. 253 - 254)
1. A solution’s pH is measuring how acidic or basic the
substance is
2. The scale ranges from 0 – 14
1.
2.
7 is neutral
0 is very acidic & 14 is very basic
3. The pH value of a solution directly relates 2 the amt. of H30+
and OH- ions within the solution
1. A neutral solution has an equal amt. of both
4. A change in pH 1 level is increasing or decreasing the acidity
by 10
1. So, a solution w/ a pH of 12 is a 100 times more basic than 10
pH & Strengths of Acids & Bases
(pg. 254 - 255)
1. Acids used in food R weak acids (5, or 6) vs. strong
acids & dangerous, harmful (1, or 2
2. A stronger acid has more hydronium ions than a weak
acid, giving it a lower pH & vice versa for bases
3. Indicators = compounds that react w/ acids & bases
producing certain colors
1. They help determine how acidic or basic a substance is
by changing a variety of colors
2. Ex: litmus paper  red for acid, blue for basic
Neutralization (pg. 255 - 256)
1. Heartburn comes from too much hydrochloric acid in
the stomach causing irritation, so you ingest a base
(antacid) 2 counteract that reaction
2. Neutralization = interaction that occurs between acids
& bases where they cancel each other’s properties
out
1. This happens b/c the hydronium & hydroxide ions
reaction 2 produce 2 water molecules (which R neutral)
 acid-base neutralization
2. When acids & bases neutralize a salt is also produced
w/ the water…salts R neither acidic or basic
All Done!!