ECAT Pre Engineering Chemistry Chapter 3 MCQ Test With Answer

Question # 1

The rate of diffusion of a gas in

Inversely proportional to its density A
Inversely proportional to square root of its molecular mass B
Directly proportional to molecular mass C
Directly proportional to its density D

Question # 2

All gases can be compressed by :

Keeping constant pressure A
Decreasing pressure B
Increasing pressure C
None of the above D

Question # 3

In gases and liquids, temperature is the measure of

Average translational kinetic energies of molecules A
Average vibrational kinetic energies of molecules B
Average rotational kinetic energies of molecules C
None of above D

Question # 4

Gases exert pressure on walls of container because the gas molecules :

Obey gas laws. A
Have definite volume. B
Collide with the walls of container. C
Collide with each other. D

Question # 5

Cooling happens under the Joule Thomson Effect due to sudden :

Contraction A
Absortption B
Expansion C
All of above D

Question # 6

All gases can be compressed by

Keeping constant pressure A
Decreasing pressure B
Increasing pressure C
None of above D

Question # 7

For a gas obeying Boyle's law if pressure is doubled, the volume becomes

Remains constant A
Double B
One half C
None of above D

Question # 8

The graph between pressure and volume at constant temperature for a gas is

Isobaric A
Isothermal B
Isotherm C
None of above D

Question # 9

The intramolecular forces in gases are

Weak A
Normal B
Very weak C
Strong D

Question # 10

In Boyle's law which of the following pair is variable :

Temperature and quantity of a gas. A
Pressure and volume B
Volume and quantity of a gas. C
Pressure and quantity of a gas. D

Question # 11

The deviation of a gas from ideal behavior is maximum at :

-10°C and 5.0 atm A
-10°C and 2.0 atm B
100°C and 2.0 atm C
0°C and 2.0 atm D

Question # 12

The movement of molecules from a region of high pressure to vacuum is called :

Evaporation A
Effusion B
Conduction C
Difusion D

Question # 13

Which statement about gases is not correct ?

The spread throughout the vessel. A
Pressure is due to collision B
There are large spaces between the molecules. C
molecules are arranged regularly. D

Question # 14

According to Boyle's law, which parameters give a straight line parallel to axis-s, when we plot a graph between:

V and T A
P and V B
P and 1/V C
P and PV D

Question # 15

Number of molecules in one dm³of water is close to :

6.02/22.4

A
12.04/22.4 *10²³

B
18/22.4*10²³
C
55.6*6.02*10²³* 10²³
D

Question # 16

Which of the following will have the same number of molecules at STP ?

280 CM³ of CO² and 280 CM³ of N₂O
A
11.2 dm3 of O₂ and 32 g of O₂
B
44 g of CO₂ and 11.2 dm³ of CO
C
28 g of N2 and 5.6 dm³ of oxygen
D

Question # 17

Keeping the temperature constant, if the gas is expanded

kinetic energy of molecules will increase A
Number of gas molecules increases B
Temperature will increases C
Pressure will decrease D

Question # 18

The density of a gas is directly proportional to pressure, inversely proportional to temperature and directly proportional to

Viscosity A
Molar mass B
Momentum C
All of above D

Question # 19

Which of the following is the simplest form of matter?

Gaseous state A
Liquid state B
Solid state C
All of above D

Question # 20

Pressure remaining constant, at which temperature volume of gas will become twice of what it is at 0°C ?

546
A
200 B
546K C
273K D

Question # 21

A graph b/w P and 1/V at constant temperature and number of moles is parallel to :

None of above A
X-axis B
Z-axis C
Y-axis D

Question # 22

In Boyle's law which of the following pair remains constant

Temperature and quality of a gas A
Pressure and quality of a gas B
Temperature and pressure C
Temperature and quantity of a gas D

Question # 23

Cooling happens under the Joule Thomson Effect due to sudden

Contraction A
Absorption B
Expansion C
All of above D

Question # 24

Gases show uniform behaviour towards their

Internal conditions A
External conditions B
Internal and external conditions C
None of above D

Question # 25

Gases of air, always remain in random motion and do not settle due to

Difference in molecular masses of air gases A
Difference in partial pressure of gas molecules B
Unequal number of different gas molecules C
Elastic collision of gas molecules D

Question # 26

Which Statement about gases is not correct?

They spread throughout the vessel A
Pressure is due to collision B
There are larger spaces between the molecules C
Molecules are arranged regularly D

Question # 27

Boyle's law doesn't fail even :

Temperature is extremely high A
Pressure is extremely high B
Mixture of gas is taken C
All of above D

Question # 28

Gases exert pressure on walls of container because the gas molecules

Obey gas laws A
Have definite volume B
Collide with the walls of container C
Collide with each other D

Question # 29

In solids, the temperature of is the measure of

Rotational kinetic energies A
transnational kineticenergies B
Vibrationalkineticenergies C
None of the above D

Question # 30

If absolute temperature of a gas is doubled and the pressure is reduced to one half, the volume of gas will :

remain unchanged A
increase four times B
reduce to 1/4 C
be doubled D

Sr.#	Question	Answer
1	Number of molecules in one dm³of water is close to :	A. 6.02/22.4 B. 12.04/22.4 10²³ C. 18/22.410²³ D. 55.66.0210²³* 10²³
2	In gases and liquids, temperature is the measure of :	A. Average transnational kinetic energies of molecules. B. Average vibrational kinetic energies of molecules. C. Average rotational kinetic energies of molecules. D. None of above
3	In Boyle's law which of the following pair remains constant :	A. Temperature and quality of a gas. B. Pressure and quality of a gas. C. Temperature and pressure D. Temperature and quantity of a gas.
4	The intramolecular forces in gases are	A. Weak B. Normal C. Very weak D. Strong
5	Absolute temperature of a gas is proportional to	A. Rotational kinetic energy B. Translational kinetic energy C. Vibrational kinetic energy D. Potential energy
6	The ratio of volume to temperature on Kelvin scale is constant according to	A. Charle's law B. Newton's law C. Coulomb's law D. Boyle's law
7	All gases can be compressed by :	A. Keeping constant pressure B. Decreasing pressure C. Increasing pressure D. None of the above
8	Gases deviate from ideal behavior at high pressure. Which of the following is correct for non-ideality ?	A. At high pressure, the gas molecules move in one direction only. B. At high pressure, the collisions between the gas molecules are increased manifold. C. At high pressure, the volume of gas becomes insignificant. D. At high pressure, the inter molecular attraction become significant.
9	The rate of diffusion of a gas in	A. Inversely proportional to its density B. Inversely proportional to square root of its molecular mass C. Directly proportional to molecular mass D. Directly proportional to its density
10	Pressure remaining constant, at which temperature volume of gas will become twice of what it is at 0°C ?	A. 546 B. 200 C. 546K D. 273K

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