Matter in our surrounding Worksheet-3

Matter in our surrounding Worksheet-3

21. The interparticle forces are the strongest in :

A. Ammonia                                  B. Ethyl alcohol

C. Carbon dioxide                        D. Sodium bromide

22. Evaporation of a liquid can take place :

A. at its boiling point                   B. below its boiling point

C. at all temperatures                 D. at a fixed temperature.

23. ln the sublimation process :

A. solid changes directly to the vapour state.

B. solid initially melts and then changes to vapour state.

C. liquid changes to vapour state.

D. None of the options is correct.

24. The evaporation of a liquid can be best carried in a-

A. beaker           B. china dish     C. test tube        D. flask

25. Sulphur dioxide is collected in the laboratory in a gas jar by upward displacement of air. Which of the following statements is correct regarding the density of the gas?

A. It is heavier than air

B. It is lighter than air

C. Its density is equal to that of air

D. No correct statement can be made about the density of the gas.

26. A liquid is kept in an open china dish. The evaporation of the liquid can be accelerated_____.

A. by keeping the dish in the open

B. by blowing air into the liquid

C. by keeping the dish under a running fan

D. All are correct

27. In which form is zinc metal generally available in the chemistry laboratory ?

A. as pellets                          B. as a rod

C. as fine filings                   D. as granules

28. The melting point temperature of the solid state and freezing point temperature of the liquid state of the same substance are :

A. both same                        B. both different

C. may vary slightly            D. None is correct

29. The least count of a thermometer employed to determine the boiling point of water is :

A. 0.5°C                                B. 0.1°C

C. 1°C                                     D. None of these

30. Mercury is generally used in glass thermometers because :

A. it can be easily seen

B. it does not stick to glass

C. it remains in the liquid state over wide temperature range

D. All are correct.

Answer Key:

21. D

Explanation: Sodium bromide is an ionic solid and there is strong electrostatic force of attraction between the ions. So Sodium bromide does not sublime.

22. C

Explanation: Evaporation is a surface phenomenon and it takes place at all temperatures.

23. A

24. B

Explanation: Among the given options China dish has maximum surface area so maximum evaporation will take place from china dish.

25. A

Explanation: The density of gas is more than air.

26. D

27. D

Explanation: Zinc generally exists in granular form.

28. A

Explanation: Pure, crystalline solids have a characteristic melting point, the temperature at which the solid melts to become a liquid. The melting point of solid oxygen, for example, is –218.4ºC.

Liquids have a characteristic temperature at which they turn into solids, known as their freezing point. In theory, the melting point of a solid should be the same as the freezing point of the liquid. In practice, small differences between these quantities can be observed.

29. A

30. D