Chemistry · Science General

States of Matter

2,682 Questions

States of matter questions explore physical changes, evaporation, phase transitions, and the properties of liquids and gases. Topics cover density, cryosurgery, heavy water, and electrolytes. This foundational chemistry topic frequently appears in general science sections of SSC and railway exams.

Phase change mechanismsEvaporation and temperature effectsProperties of liquidsPhysical versus chemical changesElectrolytes and heavy water

States of Matter Questions

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

What happens to the rate of evaporation when there is more exposed surface area of liquid?

  1. It decreases gradually

  2. It increases

  3. Remains same

  4. It decreases rapidly
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation is a process in which some molecules of a liquid, which have greater kinetic energy, escape from the liquid and enter the atmosphere.

When the surface area exposed is more, the molecules get greater opportunity to escape. Hence more molecules escape and rate of evaporation increases.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

The moving air from the hair dryer removes the molecules of liquids as soon as they escape from the surface of your  hair.
Which factor of evaporation is responsible for the above example?

  1. Temperature

  2. Motion of air

  3. Nature of liquid

  4. Humidity of surrounding
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation is a process in which some molecules of a liquid, which have greater kinetic energy, escape from the liquid and enter the atmosphere.

Evaporation occurs faster at a higher temperature.
The wind of the hairdryer being hotter than room temperature, speeds up the evaporation process.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Choose the correct statements from the following

  1. Evaporation takes place from the surface of a liquid at all temperatures.

  2. The rate of evaporation depends upon the area of the exposed surface of the liquid, nature of the liquid and its temperature.

  3. The rate of evaporation depends on the pressure to which the liquid is subjected.

  4. The cooling produced in evaporation is a consequence of the fact that a liquid has latent heat.
Reveal answer Fill a bubble to check yourself
A,B,C,D Correct answer
Explanation

Evaporation is a type of vaporization of a liquid that occurs from the surface of a liquid into a gaseous phase. So there is loss of energy due to latent heat of the liquid.

For molecules of a liquid to evaporate, they must be located near the surface, they have to be moving in the proper direction, and have sufficient kinetic energy to overcome liquid-phase inter-molecular forces. When only a small proportion of the molecules meet these criteria, the rate of evaporation is low. Since the kinetic energy of a molecule is proportional to its temperature, evaporation proceeds more quickly at higher temperatures and high surface area.
Evaporation happens faster if there is less exertion on the surface keeping the molecules from launching themselves.
So all the options are correct.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Soda bottles are made of thick glass so that they can withstand an increase in :

  1. pressure during summer

  2. temperature during summer

  3. viscosity

  4. potential energy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Gas, liquid and solid expand on heating.
Gas expands the max. due to free of gas molecules or almost zero force of attraction between them. On heating they gain K.E. and move up to any place. This gives expansion of gases.
The pressure of gas inside closed container increases upon heating. This is seen that soda bottle explodes in summer. So the air made up of thick glass so that they can withstand pressure.
Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

When the temperature of water rises, the rate of evaporation decreases. State whether true or false.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The statement if False.
Actually, rate of evaporation of a liquid decreases as the temperature decreases. As intermolecular force increase rate of evaporation decreases. This happens because intermolecular force make it less likely for the molecules on the surface to escape from liquid and become vapour gas. As temperature increases rate of evaporation increases.
Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Why mercury do not evaporate at room temperature?

  1. Because melting point of mercury is higher

  2. Because boiling point of mercury is higher

  3. Because boiling point of mercury is lower

  4. Because boiling point of mercury is equal to room temperature
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation is a process in which some molecules of a liquid, which have greater kinetic energy, escape from the liquid and enter the atmosphere.

When the temperature of the liquid is closer to its boiling point, greater is the evaporation. 
Besides the boiling point being higher, the cohesive force of attraction among the molecules of mercury is greater than other liquids like water. This further reduces the evaporation rate.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Evaporation is the process of changing liquid into vapour below its boiling point. State whether true or false.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Evaporation is the process of changing liquid into vapour below B.P. (boiling point)
It is the type of vaporisation that occurs on the surface of liquid due to increase in temperature or pressure it changes liquid into gaseous phase before reaching to B.P. The surrounding gas must not be saturated by evaporating substance.
Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

The molecules of liquid change into vapour when the pressure of molecules of liquid

  1. exceeds the atmospheric pressure

  2. becomes less than the atmospheric pressure

  3. becomes equal to the atmospheric pressure

  4. becomes zero
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When the pressure of molecules of liquid become equal to the atmospheric pressure, the molecules of liquid change into vapours.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Water in an earthen pitcher gets cooled due to

  1. slower rate of evaporation

  2. faster rate of evaporation

  3. no evaporation at all

  4. some unknown reason
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Earthen pots are used in summer. The pot has several pores through which water rinses out to the outer surface of the earthen pot and evaporates. In this process it takes away heat from the water inside the pitcher. As a result, the water inside gets cooled.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

What is not true about evaporation?

  1. Greater the surface area of the liquid, the quicker is the evaporation

  2. Evaporation produces cooling

  3. Evaporation takes place at all the temperatures

  4. Evaporation is nothing but boiling at the highest temperature of the liquid
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Evaporization is the vaporization process of converting the liquid phase to vapour phase when surrounding temperature is more than liquid / water temperature.

It should not be confused with boiling as boiling means whole phase change from liquid to vapour at highest temperature.