Chapter 18: Chemical Tests

Question 1

Why must litmus paper be dampened before use with ammonia gas?

Answer 1

because ammonia gas reacts with the water on the litmus paper to form ammonium hydroxide and litmus paper turns blue in the presence of hydroxide ions.

Question 2

What is the example equation for copper (sulphate) and sodium hydroxide reacting?

Answer 2

Copper (sulphate) + sodium hydroxide-> copper hydroxide + sodium (sulphate)

Question 3

What is the example equation for ammonium (chloride) + sodium hydroxide reacting?

Answer 3

Ammonium (chloride) + sodium hydroxide -> sodium chloride + ammonia + water

Question 4

What is the example equation for zinc carbonate and nitric acid reacting?

Answer 4

Zinc carbonate + nitric acid -> zinc nitrate + carbon dioxide + water

Question 5

What is the example equation for barium chloride and sodium sulphate reacting?

Answer 5

Barium chloride + sodium sulphate -> sodium chloride + barium sulphate

Question 6

What is the example equation for silver nitrate and sodium bromide reacting?

Answer 6

Silver nitrate + sodium bromide -> sodium nitrate + silver bromide

Question 7

What happens when carbon dioxide and limewater react?

Answer 7

a white precipitate of calcium carbonate forms