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

Bio gas production is more useful when compared to the direct use of dung because

• both fuel value and fertiliser value are effectively utilised

• production of bio gas involves less labour

• fuel is quickly produced

• the fertiliser produced is a fluid

138.

In blast furnace, iron oxide is reduced by

• hot blast of air

• carbon monoxide

• carbon

• silica

Use of chlorofluoro carbons is not encouraged because

• they are harmful to the eyes of people that use it

• they damage the refrigerators and air conditioners

• they eat away the ozone in the atmosphere

• they destroy the oxygen layer

Conversion of oxygen into ozone is non-spontaneous at

• all temperature

• high temperature

• room temperature

• low temperature