Topic 3: Chemical Changes

Question 1

What is the pH of an acid?

Answer 1

Less than 7

Question 2

What is the pH of an alkali?

Answer 2

More than 7

Question 3

What happens in a neutralisation reaction?

Answer 3

An acid reacts with a base to form salt and water

Question 4

What is the general formula for acid + metal reaction?

Answer 4

Acid + Metal → Salt + Hydrogen

Question 5

What is the general formula for acid + base reaction?

Answer 5

Acid + Base → Salt + Water

Question 6

What is a strong acid?

Answer 6

An acid that completely ionises in solution

Question 7

What is a weak acid?

Answer 7

An acid that only partially ionises in solution

Question 8

What is the reactivity series?

Answer 8

A list of metals in order of reactivity

Question 9

What is a displacement reaction?

Answer 9

A more reactive metal displaces a less reactive one from a compound

Question 10

What is an ionic equation?

Answer 10

An equation showing only the ions involved in a reaction

Question 11

What is a half equation?

Answer 11

An equation showing the gain or loss of electrons during a reaction