Matter in our surrounding Worksheet-3
A. Ammonia B. Ethyl alcohol
C. Carbon dioxide D. Sodium bromide
A. at its boiling point B. below its boiling point
C. at all temperatures D. at a fixed temperature.
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.
A. beaker B. china dish C. test tube D. flask
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.
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
A. as pellets B. as a rod
C. as fine filings D. as granules
A. both same B. both different
C. may vary slightly D. None is correct
A. 0.5°C B. 0.1°C
C. 1°C D. None of these
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.
Explanation: Sodium bromide is an ionic solid and there is strong electrostatic force of attraction between the ions. So Sodium bromide does not sublime.
Explanation: Evaporation is a surface phenomenon and it takes place at all temperatures.
Explanation: Among the given options China dish has maximum surface area so maximum evaporation will take place from china dish.
Explanation: The density of gas is more than air.
Explanation: Zinc generally exists in granular form.
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.