Qualitative Analysis

Question 1

What is the test for Carbonate ions?

Answer 1

Add Acid such as dilute hydrochloric acid
If present
Bubbles form
Limewater Cloudy

Question 2

What is the test for sulfate ions?

Answer 2

Add barium chloride(Solution containing barium ions)
If present white precipitate forms

Question 3

What is the test for chloride ion?

Answer 3

Add aqueous silver nitrate
If present white precipitate forms

Question 4

What is the test for Bromide ion?

Answer 4

Add aqueous silver nitrate
If present cream precipitate forms.

Question 5

What is the test for Iodide ion?

Answer 5

Add aqueous silver nitrate
If present yellow precipitate forms.

Question 6

For a follow up test after adding silver nitrate, what is the test for chloride ion?

Answer 6

Add dilute ammonia and if present precipitate dissolves.

Question 7

For a follow up test after adding silver nitrate, what is the test for bromide ions?

Answer 7

Add concentrated ammonia and if present it dissolves.

Question 8

For a follow up test after adding silver nitrate, what is the test for iodide ions?

Answer 8

Add concentrated ammonia and if present it does not dissolve.

Question 9

What is the test for ammonium cations?

Answer 9

Add sodium hydroxide.
If present then litmus paper turns from red to blue as its an alkaline.

Question 10

What is the sequence of tests you should carry out for anions?
If you are asked to analyse an unknown inorganic compound.

Answer 10

The correct order is
Carbonate- 1st
Sulfate- 2nd
Halide- 3rd

Question 11

Why is it important to carry out the Carbonate test before the Sulfate test?

Answer 11

In the sulfate test you are looking for a white precipitate when adding a solution containing Ba 2 plus ions.
But if you get barium carbonate this is a white precipitate too.
Therefore it is important to test for carbonate 1st and only proceed to the sulfate test when you know that no carbonate is present.