6.3 Neutralisations reactions

Question 1

How can you make soluble salts?

Answer 1

• By reacting an acid with a metal, an insoluble metal hydroxide or a metal carbonate.
• Add the insoluble substance to the acid - they will react to produce a soluble salt (plus either water, hydrogen or water and carbon dioxide).
• You will know when all the acid has been reacted because the excess solid will just sink to the bottom of the flask.
• Then filter off the excess solid to get a solution containing only salt and water.
• Heat the solution gently to slowly evaporate off some of the water, then leave the more concentrated solution to cool and allow the salt to crystallise. Filter off the solid and leave it to dry.

Question 2

When metal oxides react with an acid, what do they produce?

Answer 2

Salt and water

Question 3

When metal hydroxides react with an acid, what do they produce?

Answer 3

Salt and water

Question 4

Describe how metal oxides/metal hydroxides react with acid to form salt and water

Answer 4

The negative ions from the acid combines with the positive ions from the base to form salt, and you always get water.

Question 5

When metal carbonates react with an acid, what do they produce?

Answer 5

A salt, water and carbon dioxide

Question 6

What type of reaction is it when an acid and a base react together?

Answer 6

Neutralisation reaction

Question 7

During a neutralisation reaction, the positive __________ ions from the acid react with the negative _____________ ions from the alkali to form molecules of water.

Answer 7

hydrogen, hydroxide

Question 8

How do you work out the formula of a salt that is formed from an acid and an insoluble reactant?

Answer 8

To work out the formula of the salt, take the positive ion from the base, such as sodium from sodium oxide (NaO) and the negative ion from the base, such as chloride from hydrochloride acid (HCl), and combine them together.