R4RIN – MCQs, Mock Tests | CBES Board Class 9 PHYSICAL STATES OF MATTER MCQS CLASS 9

The process in which the solid changes directly into vapors without changing in the liquid state is called

1. condensation
2. evaporation
3. boiling
4. sublimation

✅ Correct Answer: 4

Conversion of a liquid to a gas at all temperatures is called

1. sublimation
2. evaporation
3. condensation
4. boiling

✅ Correct Answer: 2

The temperature at which the solid starts melting is called

1. boiling point
2. freezing point
3. melting point
4. sublimating point

✅ Correct Answer: 3

At constant pressure the average kinetic energy of gas molecules increases 2 times if

1. temperature is increased by 2 times
2. temperature is halved
3. no change in temperature
4. temperature remains constant

✅ Correct Answer: 1

The average kinetic energy of gas molecules is directly proportional to

1. T2
2. ?T
3. T
4. 2T

✅ Correct Answer: 3

The mathematical expression that describes Boyles law is

1. PV = constant
2. V * constant = P
3. P * constant = V
4. V ? P = constant

✅ Correct Answer: 1

For a certain reaction PV = 2 dm3 atm and volume is 4 dm3 then the corresponding pressure is

1. 1 atm
2. 4 atm
3. 0.5 atm
4. 2 atm

✅ Correct Answer: 3

The molecules of liquid which escape first have

1. highest kinetic energy
2. lowest kinetic energy
3. moderate kinetic energy
4. infinite kinetic energy

✅ Correct Answer: 1

The pressure that vapors apply on the surface of the liquid at equilibrium is called

1. torr
2. vapor pressure
3. liquid pressure
4. condensation

✅ Correct Answer: 2

On increasing the temperature of amorphous solid they

1. melt at specific temperature
2. soften gradually
3. break at specific temperature
4. boil at specific temperature

✅ Correct Answer: 2

The movement of molecules from higher concentration to lower concentration is called

1. diffusion
2. concentration
3. effusion
4. mobility

✅ Correct Answer: 1

At Mount Everest the water boils at

1. 100 �C
2. 90 �C
3. 80 �C
4. 70 �C

✅ Correct Answer: 4

The barometer is invented by

1. Galileo
2. Robert Boyle
3. Charles
4. Torricelli

✅ Correct Answer: 4

The melting and freezing of a substance occurs as

1. same temperature
2. more than melting point
3. more than freezing point
4. less than boiling point

✅ Correct Answer: 1

If the liquid is heated to increase the kinetic energy then the liquid will

1. evaporate slowly
2. evaporate faster
3. not evaporate
4. boil

✅ Correct Answer: 2

Solids whose atoms arrange themselves in different forms are

1. isotopes
2. crystals
3. allotropes
4. amorphous

✅ Correct Answer: 3

The process in which the vapor molecules are recaptured by the molecules at the liquid surface is called

1. evaporation
2. sublimation
3. condensation
4. boiling

✅ Correct Answer: 3

1 atmospheric pressure is equal to

1. 100.345 Pa
2. 760 kPa
3. 101.325 kPa
4. 1.01325 mmHg

✅ Correct Answer: 3

A gas that shields living things on the surface of the earth from harmful UV radiation is

1. N2
2. SO2
3. O2
4. O3

✅ Correct Answer: 4

In graphite the carbon atoms are arranged in layers of

1. pentagonal arrays
2. heptagonal arrays
3. octagonal arrays
4. hexagonal arrays

✅ Correct Answer: 4

As the molecular mass of gasses increases their density

1. decreases
2. increases
3. remains constant
4. none of above

✅ Correct Answer: 2

The position of liquid molecules are

1. fixed
2. not fixed
3. not sliding
4. none of above

✅ Correct Answer: 2

On applying pressure the volume of gas

1. increases
2. remains same
3. becomes double
4. decreases

✅ Correct Answer: 4

Boiling point is the temperature at which vapor pressure is

1. more than external pressure
2. less than external pressure
3. not related to external pressure
4. equal to external pressure

✅ Correct Answer: 4

In a pressure cooker the pressure applied is

1. 1 atm
2. 2 atm
3. 3 atm
4. 4 atm

✅ Correct Answer: 2

If the temperature of any gas is increased its volume

1. increases
2. decreases
3. remains same
4. none of above

✅ Correct Answer: 1

An ordered repeating three-dimensional arrangement of particles makes up a

1. crystalline solid
2. amorphous solid
3. non crystalline solid
4. none of above

✅ Correct Answer: 1

The escape of gas molecules from a small hole one after the other is called

1. diffusion
2. effusion
3. concentration
4. mobility

✅ Correct Answer: 2

Force exerted by a gas on unit area of the container is called

1. effusion
2. diffusion
3. mobility
4. pressure

✅ Correct Answer: 4

At constant temperature when pressure is decreased the average kinetic energy of gas molecules

1. decreases
2. remains unchanged
3. decreases
4. becomes two fold

✅ Correct Answer: 2