From NH₃, HCl, H₂S, SO₂ – Select :

(i) The gas which when bubbled through CuSO₄ soln., a deep blue coloured soln. is formed.

(ii) This gas burns in oxygen with a green flame.

Write the equation for the reaction in the Haber’s process that forms ammonia.

Name the ion other than ammonium ion formed when ammonia dissolves in water.

Write an equation for the reaction of chlorine with excess of ammonia.