The gas which is responsible to stop ultraviolet radiation coming from the sun is _____.

1. 1. carbon dioxide
   2. Sulphur dioxide
   3. Ozone
   4. Nitrogen

Indicate an air pollutant among the following_____.

1. 1. Oxygen
   2. Nitrogen
   3. Water
   4. Carbon monoxide

A solution is _____ while a suspension is not.

1. 1. non homogenous
   2. immiscible
   3. homogenous
   4. miscible

If a gas at constant temperature and pressure expands, then its _____.

1. 1. Entropy increases and then decreases
   2. Internal energy decreases
   3. Internal energy increases
   4. Internal energy remains constant

The enthalpy change of a reaction does not depend on _____.

1. 1. Initial and final enthalpy change of reaction
   2. State of reactants and products
   3. Different intermediate reactions
   4. Nature of reactants and products

Production of chlorofluorocarbons (CFC) gas which is proposed to be banned in India is used in which of the following domestic products?

1. 1. Refrigerator
   2. Tubelight
   3. Television
   4. Cooking gas

Fluorocarbons are effective scavenger for ozone due to _____.

1. 1. Photolytic reaction of O₂ producing Cl radicals
   2. Photolytic decomposition of O3 producing O₂
   3. Photolytic decomposition of O3 into Cl and O₂
   4. Photolytic production of oxides of nitrogen

Which of the following solutions will have the highest boiling point?

1. 1. 1% NaCl in water
   2. 1% Sucrose in water
   3. 1% CaCl₂ in water
   4. 1% glucose in water

The engines of the rocket that helped the Apollo II spacecraft to land on the moon used _____ for rocket fuel power.

1. 1. Hydrazine
   2. Propane
   3. H₂
   4. O₂

A closed flask contains water in all its three states, solids, liquid and vapour at 0°C. In this situation the average K.E of the water molecule will be _____.

1. 1. Maximum in solid state
   2. Same in all the three states
   3. Maximum in vapour state
   4. Greater in the liquid than in vapour state