Testing For Ions

Question 1

Sulfates

Answer 1

Most sulfates are soluble in water except barium sulphate
Add hydrochloric acid, then barium chloride, if there is a white precipitate it is barium sulfate.
So the substance has sulfates ions.

Question 2

Hallides

Answer 2

Add nitric acid
Then silver nitrate
Precipitates will form if present
Silver chloride is white
Silver bromide is cream
Silver iodide is yellow

Question 3

Colour of silver chloride

Answer 3

White

Question 4

Colour of silver bromide

Answer 4

Cream

Question 5

Colour of silver iodide

Answer 5

Yellow

Question 6

How can you tell apart Hallide precipitates?

Answer 6

Silver chloride dissolves in both dilute and concentrated ammonia.
Silver bromide dissolves in concentrated but not dilute.
Silver iodide dissolves in neither dilute nor concentrated.

Question 7

How do you test for ammonia compounds?

Answer 7

Add sodium hydroxide warm.

If ammonia gas is given off ammonium ions are present. Alkaline turns red litmus blue.

Question 8

Carbonates

Answer 8

Add dilute acid
If present carbon dioxide will be produced
Use lime water, carbon dioxide turns it cloudy