4.4.2.2 - Neutralisation of acids and salt production

What is an acid?

An acid is a substance that forms an aqueous solution with a pH less than 7 

And forms H+ ions in water

What is a base?

A base Is a substance with a pH greater than 7

What is an alkali?

An alkali is a base that dissolves in water to form a solution with a pH greater than 7 (A soluble base)

Alkalis forms OH- ions in water

What is the reaction of an acid and a base called?

Neutralisation

Give the general word equation for neutralisation.

ACID + BASE = SALT + WATER

What are acids neutralised by?

By alkalis and bases to produce salts and water

Give an examples of alkalis that can neutralise acids?

• Soluble metal hydroxides

Give some examples of bases that can neutralise an acid.

• Insoluble metal oxides

• Insoluble metal hydroxides

What is produced when metal oxides and metal hydroxides react with acid?

Salt and water (all of the react the same)

What other substance can neutralise acids?

Metal carbonates

What is produced by the neutralisation of acids by metal carbonates?

ACID + METAL CARBONATE = SALT + WATER + CARBON DIOXIDE

What does the particular salt produced in a reaction between a salt and a base / alkali depend on?

• The acid used

• (hydrochloric acid produces chlorides, nitric acid produces nitrates, sulfuric acid produces sulfates)

• The positive ions in the base, alkali or carbonate.