Test for sulphates

Question 1

What reaction occurs if you add barium chloride solution to a solution containing sulphates?

Answer 1

barium chloride + copper(II) sulphate -> barium sulphate + copper(II) chloride

Question 2

True or False:
Barium sulphate will only appear if sulphate ions are present

Answer 2

True

Question 3

Is Barium Sulphate soluble or insoluble?

Answer 3

insoluble

Question 4

How will barium sulphate appear?

Answer 4

white precipitate

Question 5

Method

Answer 5

1. Add a few drops of hydrochloric acid.
2. Then add a few drops of barium chloride
3. If sulphate ions are present a white precipitate will appear

Question 6

What compound is responsible for the white precipitate?

Answer 6

barium sulphate

Question 7

Why must you add the hydrochloric acid first?

Answer 7

The hydrochloric acid reacts with metal carbonate to remove any carbonate. If the carbonate isn’t removed, the ppt could be either barium sulphate or barium chloride

Question 8

Why could you not use sulphuric acid?

Answer 8

Sulphuric acid contains sulphate which is what you are testing for - it will automatically be positive