A summarized discussion of acids and bases for Grade VII

2. ACIDS AND BASES
• Acids and bases are familiar compounds that
can be found at home.

3. • Hydrochloric acid is the main constituent of
gastric fluid in the stomach.
• The bases sodium bicarbonate and calcium
carbonate are ingredients in antacids, which
help relieve an upset stomach.

4. PROPERTIES OF ACIDS
• Acidus : sour
• Acetum: vinegar
1. Acids taste sour
The taste of vinegar is caused by acetic acid.
Lemons and citrus fruits have a biting taste because
they contain citric acid
2. Acids react with certain metals, such as magnesium,
zinc, and tin
3. When they are in aqueous solution, acids turn blue
litmus paper to red.

5. 4. Acids react with limestone.
5. Acids react with bases to form salts and
water.

6. PROPERTIES OF BASES
1. Bases taste bitter.
2. Bases feel slippery or
soapy.
3. Bases react with grease
and oils.
4. When they are in aqueous
solutions, bases turn red
litmus paper to blue.
5. Bases react with acids to
form water and salts.

7. Phenophthalein indicator
Phenolphthalein is a chemical
compound with the formula
C20H14O4 and is often
written as "HIn" or "phph" in
shorthand notation.
Phenolphthalein is often used
as an indicator in acid–base
titrations. For this application,
it turns colorless in acidic
solutions and red in basic
solutions.

8. The pH Scale
• pH is an intensive property of matter that
indicates how acidic or how basic a solution is.
• pH ranges from 1 to 14.
• pH 7 neutral.
• A pH below 7 indicates an acidic solution
• A pH greater than 7 indicates a basic or
alkaline solution.