Matter in our Surrounding MCQ
1. Which one of the following sets of phenomena would increase on raising
the temperature?
(a) Diffusion, evaporation, compression of gases
(b) Evaporation, compression of gases, solubility
(c) Evaporation, diffusion, expansion of gases
(d) Evaporation, solubility, diffusion, compression of gases
Ans. (c) Evaporation, diffusion, expansion of gases
Explanation: Evaporation happens because of conversation of liquid into gas and this happens because of absorption of temperature by the liquid. Hence, rise in temperature increase the rate of evaporation. Rise in temperature increase the kinetic energy of particles and gases expand on rise in temperature. Increased kinetic energy of particles
also increases diffusion.
2. Seema visited a Natural Gas Compressing Unit and found that the gas can be liquefied under specific conditions of temperature and pressure. While sharing her experience with friends she got confused. Help her to identify the correct set of
conditions
(a) Low temperature, low pressure
(b) High temperature, low pressure
(c) Low temperature, high pressure
(d) High temperature, high pressure
Ans. (c) Low temperature, high pressure
Explanation: Low temperature reduces the kinetic energy of particles. High pressure reduces intermolecular space. Both these conditions help in turning a gas into liquid.
3. The property to flow is unique to fluids. Which one of the following statements is correct?
(a) Only gases behave like fluids
(b) Gases and solids behave like fluids
(c) Gases and liquids behave like fluids
(d) Only liquids are fluids
Ans. (c) Gases and liquids behave like fluids
Explanation: In gases and liquids, space between molecules is enough which facilitates the flow of these matters.
4. During summer, water kept in an earthen pot becomes cool because of the phenomenon of
(a) diffusion
(b) transpiration
(c) osmosis
(d) evaporation
Ans. (d) evaporation
Explanation: Evaporation reduces the temperature of surroundings. Due to this, water in earthen pot cools down.
5. A few substances are arranged in the increasing order of ‘forces of attraction’ between their particles. Which one of the following represents a correct arrangement?
(a) Water, air, wind
(b) Air, sugar, oil
(c) Oxygen, water, sugar
(d) Salt, juice, air
Ans. (c) Oxygen, water, sugar
Explanation: Forces of attraction between particles is the least in gases and is maximum in solids.
6. On converting 25°C, 38°C and 66°C to kelvin scale, the correct sequence of
temperature will be
(a) 298 K, 311 K and 339 K
(b) 298 K, 300 K and 338 K
(c) 273 K, 278 K and 543 K
(d) 298 K, 310 K and 338 K
Ans. (a) 298 K, 311 K and 339 K
Explanation: 25oC + 273 = 298 K, 38oC + 273 = 311 K, 66oC + 273 = 339K.
7. Choose the correct statement of the following
(a) conversion of solid into vapours without passing through the liquid state is called vapourisation.
(b) conversion of vapours into solid without passing through the liquid state is called sublimation.
(c) conversion of vapours into solid without passing through the liquid state is called freezing.
(d) conversion of solid into liquid is called sublimation.
Ans. (b) conversion of vapours into solid without passing through the liquid state is called sublimation.
8. The boiling points of diethyl ether, acetone and n-butyl alcohol are 35°C, 56°C and 118°C respectively. Which one of the following correctly represents their boiling points in kelvin scale?
(a) 306 K, 329 K, 391 K
(b) 308 K, 329 K, 392 K
(c) 308 K, 329 K, 391 K
(d) 329 K, 392 K, 308 K
Ans. (c) 308 K, 329 K, 391 K
Explanation: Add 273 to each Celsius scale to convert them to Kelvin scale.
9. Which condition out of the following will increase the evaporation of water?
(a) Increase in temperature of water
(b) Decrease in temperature of water
(c) Less exposed surface area of water
(d) Adding common salt to water
Ans. (a) Increase in temperature of water
Explanation: The rest of the options reduce the rate of evaporation of water.
10. In which of the following conditions, the distance between the molecules of hydrogen gas would increase?
(i) Increasing pressure on hydrogen contained in a closed container
(ii) Some hydrogen gas leaking out of the container
(iii) Increasing the volume of the container of hydrogen gas
(iv) Adding more hydrogen gas to the container without increasing the volume of the container
(a) (i) and (iii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
Ans. (c) (ii) and (iii)
Explanation: Increase pressure to adding more hydrogen gas to the container without increasing the volume of container will reduce the intermolecular distance.
