ECAT Pre Engineering Chemistry Chapter 3 MCQ Test With Answer

Question # 1

Cooling happens under the Joule Thomson Effect due to sudden

Contraction A
Absorption B
Expansion C
All of above D

Question # 2

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

Remain unchanged A
Doubled B
Reduced C
Increased four times D

Question # 3

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

Evaportation A
Effusion B
Conduction C
Diffusion D

Question # 4

Gases show uniform behaviour towards their

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

Question # 5

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 # 6

The rate of diffusion of a gas is :

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 # 7

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 # 8

Which of the following is the simplest form of matter?

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

Question # 9

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 # 10

Equal masses of methane and oxygen are mixed in an empty container at 25°CThe fraction of total pressure exerted by oxygen is :

1/2 A
8/9 B
1/9 C
16/17 D

Question # 11

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

Question # 12

Boyle's law is represented as :

P∞ 1/T
A
V and 1/P B
P∞P C
P∞1/P D

Question # 13

The highest temperature at which a substance can exist as a liquid is called its

Critical temperature A
Zero temperature B
Absolute temperature C
None of above D

Question # 14

The order of the rate of diffusion of gases NH₃,SO₂, CL₂, and CO₂ IS :

NH_{3 >}SO_{2 >}CL_{2 >}CO₂ A
NH_{3 >}CO_{2 >}SO_{2 >}CL₂ B
CL_{2 >}SO_{2 >}CO_{2 >}NH₃ C
NH_{3 >}CO₂_>CL_{2 >}SO₂ D

Question # 15

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 # 16

In gases and liquids, temperature is the measure of :

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

Question # 17

At constant temperature when pressure of a gas is plotted against volume, the curve is

Slanting straight line A
Parabolic B
Staight line, parallel to pressure axis C
OF neither type D

Question # 18

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 # 19

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 # 20

All gases can be compressed by

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

Question # 21

The ratio of volume to temperature on Kelvin scale is constant according to

Charle's law A
Newton's law B
Coulomb's law C
Boyle's law D

Question # 22

In Solids, the temperature is the measure of

Rotational kinetic energies A
Translational kinetic energies B
Vibrational kinetic energies C
None of above D

Question # 23

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 # 24

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 # 25

Gases deviate from ideal behavior at high pressure. Which of the following is correct for non-ideality ?

At high pressure, the gas molecules move in one direction only. A
At high pressure, the collisions between the gas molecules are increased manifold. B
At high pressure, the volume of gas becomes insignificant. C
At high pressure, the inter molecular attraction become significant. D

Question # 26

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 # 27

Absolute temperature of a gas is proportional to

Rotational kinetic energy A
Translational kinetic energy B
Vibrational kinetic energy C
Potential energy D

Question # 28

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 # 29

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

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

Question # 30

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

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

Sr.#	Question	Answer
1	Which of the following will have the same number of molecules at STP ?	A. 280 CM³ of CO² and 280 CM³ of N₂O B. 11.2 dm3 of O₂ and 32 g of O₂ C. 44 g of CO₂ and 11.2 dm³ of CO D. 28 g of N2 and 5.6 dm³ of oxygen
2	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
3	Which statement about gases is not correct ?	A. The spread throughout the vessel. B. Pressure is due to collision C. There are large spaces between the molecules. D. molecules are arranged regularly.
4	All gases can be compressed by :	A. Keeping constant pressure B. Decreasing pressure C. Increasing pressure D. None of the above
5	A graph b/w P and 1/V at constant temperature and number of moles is parallel to :	A. Y-axis B. Z-axis C. X-axis D. None of above
6	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
7	Gases of air always remain in random motion and do not settle due to :	A. Difference in molecular masses of air gases. B. Difference in partial pressure of gas molecules. C. Unequal number of different gas molecules. D. Elastic collision of gas molecules.
8	According to Boyle's law, which parameters give a straight line parallel to axis-s, when we plot a graph between:	A. V and T B. P and V C. P and 1/V D. P and PV
9	In Boyle's law which of the following pair is variable :	A. Temperature and quantity of a gas. B. Pressure and volume C. Volume and quantity of a gas. D. Pressure and quantity of a gas.
10	All gases can be compressed by	A. Keeping constant pressure B. Decreasing pressure C. Increasing pressure D. None of above

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