3.3 qualitative

Question 1

test for carbonate ions

Answer 1

1. add dilute nitric acid
2. if present, bubbles of carbon dioxide formed
3. indentified by limewater turning cloudy

Question 2

test for sulfate ions

Answer 2

1. adding barium ions to give white ppt
2. using barium chloride or barium nitrate

Question 3

test for ammonium ions

Answer 3

1. adding hydroxide ions and heating solution
2. positive = release ammonia which will turn damp red litmus paper blue

Question 4

sequence for tests

Answer 4

1. carbonate ions
2. sulfate ions
3. halide ions

Question 5

why should the test for sulfate ions be carried out in acidified conditions?

Answer 5

to ensure the removal of carbonate ions

Question 6

why should the carbonate test be peformed before the sulfate test?

Answer 6

barium carbonate is a white ppt so all cabronate ions need to be removed before barium is added or it will be a false positive test