Select the ion in each case, that would get selectively discharged from the aqueous mixture of the ions listed below:

(i) SO₄^2-, NO₃^- and OH^- ;

(ii) Pb²⁺, Ag⁺ and Cu²⁺.

Choose the correct answer from the options given : The electrolysis of acidified water is an example of :

1. Reduction
2. Oxidation
3. Redox reaction
4. Synthesis

Give a reason for : Conductivity of dilute hydrochloric acid is greater than that of acetic acid.

Name the gas that is produced at the anode during the electrolysis of acidified water.