Assertion (A): Silver is displaced by copper from the aqueous solution of silver nitrate.

Reason (R): Copper is placed below silver in the activity series.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Name

(a) a carbonate which does not decompose on heating.

(b) a nitrate which produces oxygen as the only gas.

(c) a compound which produces carbon dioxide on heating

(d) a nitrate which produces brown gas on heating.

Define :

(a) Photochemical reaction

(b) Electrochemical reaction

Give one example in each case.

Give an example of a reaction where the following are involved

(a) Evolution of heat

(b) Absorption of heat

(c) High pressure is required