What happens when a solution of an acid is mixed with a solution of a base in a test tube?

P — The temperature of the solution increases.

Q — The temperature of the solution decreases.

R — The temperature of the solution remains the same.

S — Salt formation takes place.

1. Only P

2. P and R

3. Q and R

4. P and S

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