ACIDS AND BASESpg.135

If you want to be the best, you have to do more than

the rest.

Gary Player

Gr 9’s

Gr 9’s

Hydrochloric acid HCℓ

Sulphuric acid H2SO4

Nitric acid HNO3

Well known acids:

Acetic acid CH3COOH

Well known household acid:

Sodium hydroxide NaOH

Potassium hydroxide KOH

Sodium carbonate Na2CO3

Sodium bicarbonate NaHCO3

Ammonia NH3

Well known bases:

Acidic solutions have

a sour taste.

Acids react

with most

metals to

release H2.

A base reacts with acids

(neutralises) to form a salt

and water.

Aqueous solutions of acids

and bases conduct electricity.

Soluble bases are called

alkalis.

General acids and bases (strong and weak)

pH, indicator and pH range

Litmus:

Acid - red

Base - blue

Phenolphthalein:

Acid - colourless

Base - pink

Bromothymol blue:

Acid - yellow

Base - blue

Methyl orange:

Acid - red

Base - yellow

Characteristic reactions of acids:

Acid + base → salt + water

Acid + metal → salt + hydrogen

Acid + metal oxide → salt + water

Acid + metal carbonate → salt + water + carbon dioxide

Complete and balance each of the following equations:

2HCℓ + Mg →

SALT + H2

MgCℓ2 + H2

Mgione en Cl1-ione

MgCl2

Mg2+ ions and Cl1- ions

MgCl2

Acid + metal oxide → salt + water

Complete and balance each of the following equations:

2HCℓ + Ca(OH)2 →

SALT + H2O

CaCℓ2 + 2H2OAnother example:

Complete and balance each of the following equations:

H2SO4 + Mg(OH)2 →

SALT + H2O

MgSO4 + 2H2O

Acid + metal hydroxide → salt + water

Reaction of an acid with a metal carbonate

Acid + metal carbonate salt + water + carbon dioxide

Homework (Acids and bases)

Homework:

❖ Page 139

Questions: 1, 2, 3

❖ Pages 139, 140

Questions: 4, 5

❖ Pages 141, 142, 143

Questions: 6, 7, 8, 10