31.

The pair of gases responsible for acid rain are

• H₂, O₃

• CH₄, O₃

• NO₂, SO₂

• CO, CH₄

Cataract and skin cancer are caused by

• depletion of nitric oxide

• depletion of ozone layer

• increase in methane

• depletion of nitrous oxide

On the top of mountain, water boils at

• high temperature

• same temperature

• high pressure

• low temperature

What are X and Y in the following reaction?

${\mathrm{CF}}_2{\mathrm{Cl}}_2 \stackrel{\mathrm{UV}}{\to } \mathrm{X} + \mathrm{Y}$

• CF₂Cl, Cl

• C₂F₄, Cl₂

• CFCl₂, F

• CCl₂, F₂

Which of the following statements are correct?

A. Ocean is sink for CO₂.

B. Greenhouse effect causes lowering of temperature of earth's surface.

C. To control CO emission by automobiles, usually catalytic convertor are fitted into exhaust pipes.

D. H₂SO₄, herbicides and insecticides form mist.

• C and D

• A and B

• B and D 

• A and D

Sea divers use a mixture of

• O₂, N₂

• O₂, H₂

• O₂, He

• N₂, H₂

Which of the following causes blue baby syndrome?

• High concentration of lead in drinking water.

• High concentration of sulphates in drinking water.

• High concentration of nitrates in drinking water.

• High concentration of copper in drinking water.

N₂O₄ $\rightleftharpoons$ 2NO₂ - Q

The unit of K_p for the given reaction is

• atmosphere

• atmosphere²

• atmosphere^-1

• None of these

A neutral fertiliser among these compounds is

• ammonium nitrate

• urea

• CAN

• ammonium sulphate

Drying soil invariably contains

• butyric acid

• stearic acid

• lauric acid

• linoleic acid