On adding dilute sulphuric acid to the given salt, colourless gas with a suffocating smell of burning sulphur is evolved. It turns acidified potassium dichromate paper green. Identify the gas evolved and anion present in the given salt.

Select acidic gases from the gases mentioned below:

(i) Ammonia

(ii) Sulphur dioxide

(iii) Hydrogen chloride

(iv) Chlorine

(v) Carbon dioxide

(vi) Oxygen

(vii) Hydrogen

How is the acidic nature suspected?

Write your observation when dilute sulphuric acid is added to the following:

• A metal sulphide (sodium sulphide)

Write your observation when dilute sulphuric acid is added to the following:

• A metal carbonate (sodium carbonate)

State if the following statement is true or false. Correct the false statement.

• The action of dilute sulphuric acid on marble chips produces carbon dioxide.