Acids, Alkalis and Salts

Question 1

What is an acid?

Answer 1

A substance with a pH lower than 7.

Question 2

What is a base?

Answer 2

A substance with a pH greater than 7.

Question 3

What is an alkali?

Answer 3

A base that dissolves in water.

Question 4

What ions make solutions acidic?

Answer 4

H+ ions.

Question 5

What ions make solutions alkaline?

Answer 5

OH- ions.

Question 6

What is the reaction between acids and bases?

Answer 6

Acid + Base –> Salt + Water

Question 7

What type of reaction is the reaction between acids and bases?

Answer 7

Neutralisation.

Question 8

What is the ionic equation for neutralisation?

Answer 8

H+ + OH- –> H2O

Question 9

What is the reaction of acids with metals?

Answer 9

Acid + Metal –> Salt + Hydrogen

Question 10

Why doesn’t copper react with dilute acids?

Answer 10

Less reactive than hydrogen.

Question 11

What kind of salts does hydrochloric acid produce?

Answer 11

Chloride salts.

Question 12

What kind of salts does sulfuric acid produce?

Answer 12

Sulfate salts.

Question 13

What are the reactions between acids and metal oxides/hydroxides?

Answer 13

Acid + Metal (hydr)oxide –> Salt + Water

Question 14

What is different about the neutralisation of ammonia?

Answer 14

No water is produced.

Question 15

Why is ammonium nitrate a good fertiliser?

Answer 15

It has nitrogen from two sources.

Question 16

How can you tell if the acid has been neutralised in a reaction with metals or insoluble bases?

Answer 16

Excess solid will sink.

Question 17

Why can’t you add an excess of alkali to make a soluble salt?

Answer 17

You have to add exactly the right amount of alkali to neutralise the acid.

Question 18

What kind of reaction is needed to make insoluble salts?

Answer 18

Precipitation reaction.

Question 19

What can precipitation reactions be used for?

Answer 19

Cleaning drinking water.