MCQs
1. A mixture of sand, common salt and camphor. The substance(s) which get(s) separated by sublimation is/are
(a) Sand and camphor
(b) Common salt only
(c) Camphor only
(d) Common salt and camphor
Answer. (c) Camphor only
2. Which one of the following can not be separated by sublimation?
(a) Common salt
(b) Ammonium chloride
(c) Camphor
(d) Iodine
Answer. (a) Common salt
3. In a mixture of common salt, sand and ammonium chloride, first step of separation is
(a) Filtration
(b) Crystallization
(c) Sedimentation
(d) Sublimation
Answer. (d) Sublimation
4. Out of the following the substance which can be separated from a mixture by sublimation
(a) Sugar
(b) Camphor
(c) Common salt.
(d) Chalk powder
Answer. (b) Camphor
5. The mixture of sulphur and sodium chloride can be separated by
(a) Dissolving in water followed by filtration and evaporation of filtrate
(b) Sublimation
(c) Dissolving in alcohol followed by filtration (d) Crystallization
Answer. (a) Dissolving in water followed by filtration and evaporation of filtrate
6. The aqueous mixture of salt and sand can be separated by the following method
(a) Filtration
(b) Sublimation
(c) Condensation
(d) Melting
Answer. (a) Filtration
7. A student takes a mixture of sand and ammonium chloride in a china dish and heats it under a funnel fitted with a plug over a flame. He would observe that:
(a) solid sand gets deposited on the lower cooler parts of the funnel while solid ammonium chloride remains in the china dish.
(b) sand and ammonium chloride gets deposited on hotter parts of the funnel.
(c) ammonium chloride gets deposited on the cooler parts of the funnel and sand remains in the china dish.
(d) sand collects on cooler parts of the funnel while ammonium chloride melts in the china dish.
Answer. (c) ammonium chloride gets deposited on the cooler parts of the funnel and sand remains in the china dish.
8. During melting of ice the temperature
(a) Increases
(b) Decreases
(c) Remains the same
(d) First increases then decreases
Answer. (c) Remains the same
9. When common salt is added to ice its melting point is
(a) Less than 0°C
(b) More than 0°C
(c) More than 10°C
(d) Less than -50°C
Answer. (a) Less than 0°C
10. At room temperature (30°C) a student sets up an apparatus to determine the melting point of ice. He takes a beaker half filled with ice and dips a thermometer in it. correct observation is
(a) Temperature falls and becomes constant at -4°C
(b) Temperature falls and becomes constant at 0°C till whole ice melts
(c) Temperature falls and ice starts melting with increase in temperature
(d) Temperature keeps on falling till -4°C, then it starts increasing.
Answer. (b) Temperature falls and becomes constant at 0°C till whole ice melts
11. When all ice floating in water melts, the level of water in the container
(a) Falls
(b) Rises
(c) Remains unchanged
(d) First rises, then falls
Answer. (c) Remains unchanged
12. Boiling point of water is
(a) 100°C
(b) 373 K
(c) 273.16 K
(d) (a) or (b)
Answer. (d) (a) or (b)
13. A student takes some water in a beaker and heats it over a flame for determining its boiling point. He keeps on taking its temperature readings. He would observe that the temperature of water:
(a) keeps on increasing regularly
(b) keeps on increasing irregularly
(c) first increases slowly, then decreases rapidly and eventually becomes constant
(d) first increases gradually and then becomes constant
Answer. (d) first increases gradually and then becomes constant
14. When liquid boils in open container
(a) The vapour pressure of liquid is more than atmospheric pressure
(b) The vapour pressure of liquid is less than atmospheric pressure
(c) The vapour pressure of liquid is equal to atmospheric pressure
(d) All of these
Answer. (c) The vapour pressure of liquid is equal to atmospheric pressure
15. The temperature at which solid melts is called:
(a) boiling point
(b) melting point
(c) both (a) and (b)
(d) none of these
Answer. (b) melting point
16. When temperature is increased kinetic energy of molecules:
(a) increases
(b) decreases
(c) remains same
(d) first increases then decreases
Answer. (a) increases
17. Boiling point is temperature at which liquid:
(a) changes into vapours
(b) changes into solid
(c) decreases its volume
(d) none of these
Answer. (a) changes into vapours
18.Solids mostly have melting point and boiling point:
(a) above room temperature
(b) below room temperature
(c)much below room temperature
(d) none of these
Answer. (a) above room temperature
19. Gases have melting and boiling points:
(a) below room temperature
(b) above room temperature
(c)much above the room temperature
(d) can't be predicted
Answer. (a) below room temperature
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