Choose the correct answer from the options given:

The catalyst used in the Contact Process is:

1. Copper
2. Iron
3. Vanadium pentoxide
4. Manganese dioxide

Write a balanced chemical equation for - Action of concentrated sulphuric acid on carbon.

Write balanced chemical equations for the following reactions:

Action of dilute sulphuric acid on —

(i) Sodium hydroxide

(ii) Zinc sulphide

Distinguish between the following pairs of compounds using the reagent given in the bracket:

Dilute hydrochloric acid and dilute sulphuric acid [using lead nitrate soln.]