C4.2.3 - Detecting Anions

Question 1

How do you detect sulfate ions?

Answer 1

Add a few drops of dilute hydrochloric acid
Then add a few drops of barium chloride solution
If there are sulfate ions you will get a white predicate

Question 2

How do you detect carbonate ions?

Answer 2

Add a few drops of dilute hydrochloric acid
If carbonate ions are present bubbles of gas will be produced
You can then use a limewater test to check if the gas is carbon dioxide

Question 3

Name 3 halides

Answer 3

Chloride
Bromide
Iodide

Question 4

How do you detect halide ions?

Answer 4

Add a few drops of dilute nitric acid
Then add a few drops silver nitrate solution
If a halide is present you will get: 
White precipitate (Chloride)
Cream precipitate (Bromide)
Yellow precipitate (Iodide)

Question 5

What colours are the precipates for chloride, bromide and iodide?

Answer 5

Chloride - White
Bromide - Cream
Iodide - Yellow