States of Matter

5.32. Which of the following gases will have the lowest rate of diffusion?

(a) H₂

(b) N₂

(c) F₂

(d) O₂

5.31. Viscosity of a liquid is a measure of

(a) Repulsive forces between the liquid molecules

(b) Frictional resistance

(c) Intermolecular forces between the molecules

(d) None of the above

5.30. With rise in temperature, the surface tension of a liquid

(a) Decreases 

(b) Increases

(c) Remaining the same

(d) None of the above

5.29. At constant temperature, the pressure of the gas is reduced to one-third, the volume

(a) Reduce to one-third

(b) Increases by three times

(c) Remaining the same

(d) Cannot be predicted

MCQs:

5.28. The average kinetic energy of the gas molecule is

(a) Inversely proportional to its absolute temperature

(b) Directly proportional to its absolute temperature

(c) Equal to the square of its absolute temperature

(d) All of the above

5.27. Assertion: At high altitudes, liquids boil at lower temperatures in comparison to that at sea level.

Reason: At high altitudes atmospheric pressure is high.

5.26. Assertion: Intermolecular interactions may hold the closely and slowly moving molecules together and thus the solid liquifies.

Reason: Compression brings the molecules in close vicinity and cooling slows down the movement of molecules.

5.25. Assertion: Liquids and solids are hard to compress.

Reason: Magnitude of the repulsion rises very rapidly as the distance separating the molecules decreases.

5.24. Assertion: Viscosity of liquids decreases as the temperature rises.

Reason: Molecules of liquids are held together by attractive intermolecular forces.

Assertion and Reason:

Directions:

(a) Assertion and reason both are correct statements and reason is correct explanation for assertion.

(b) Assertion and reason both are correct statements but reason is not correct explanation for assertion.

(c) Assertion is correct statement but reason is wrong statement.

(d) Assertion is wrong statement but reason is correct statement.

5.23. Assertion: The dipole-dipole interactionbetween two HCl moleculesis stronger than the London forces.

Reason: Only partial charges are involved