ECAT Pre Engineering Chemistry Chapter 3 MCQ Test With Answer

Question # 1

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 # 2

The product of pressure and volume remains constant when temperature and quantity of gas is

zero A
variable B
kept constant C
None of these D

Question # 3

How should condition be changed to prevent the volume of a given gas from expanding whine its mass is increased ?

Temperature is lowered and pressure is increased A
Temperature is increasedand pressure is lowered B
Temperature and pressure both are lowered C
Temperature and pressure both are increased D

Question # 4

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

Evaporation A
Effusion B
Conduction C
Difusion D

Question # 5

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 # 6

A graph between P and 1/V at constant temperature and number moles of a gas meets the

y-axis A
x-axis B
origin C
none of above D

Question # 7

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 # 8

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 # 9

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 # 10

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 # 11

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 # 12

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 # 13

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 # 14

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 # 15

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 # 16

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 # 17

A graph between P and PV at constant temperature and number of mole is parallel to

y axis A
z axis B
x axis C
pressure axis D

Question # 18

A real gas obeying van der Waals' equation will resemble ideal gas if :

both 'a' and 'b' are large A
both 'a' and 'b' are small B
'a' is small and 'b' is large C
'a' is large and 'b' is small D

Question # 19

Gases show uniform behaviour towards their

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

Question # 20

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 # 21

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 # 22

Cooling happens under the Joule Thomson Effect due to sudden

Contraction A
Absorption B
Expansion C
All of above D

Question # 23

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 # 24

The relation ships b/w volume of given amount of gas and prevailing conditions of temperature and pressure are :

Charles's law A
Graham's law B
Boyle's law C
Gas law D

Question # 25

Boyle's law does not fall even

Temperature is extremely high A
Pressure is extremely high B
Mixture of gases is taken C
all of above D

Question # 26

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 # 27

All gases can be compressed by

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

Question # 28

Gases shows uniform behavior toward their :

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

Question # 29

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 # 30

Cooling happens under the Joule Thomson Effect due to sudden :

Contraction A
Absortption B
Expansion C
All of above D

Sr.#	Question	Answer
1	Gases show uniform behaviour towards their	A. Internal conditions B. External conditions C. Internal and external conditions D. None of above
2	How should condition be changed to prevent the volume of a given gas from expanding whine its mass is increased ?	A. Temperature is lowered and pressure is increased B. Temperature is increasedand pressure is lowered C. Temperature and pressure both are lowered D. Temperature and pressure both are increased
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	Boyle's law is represented as :	A. P∞ 1/T B. V and 1/P C. P∞P D. P∞1/P
5	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
6	The movement of molecules from a region of high pressure to vacuum is called :	A. Evaporation B. Effusion C. Conduction D. Difusion
7	The order of the rate of diffusion of gases NH₃,SO₂, CL₂, and CO₂ IS :	A. NH_{3 >}SO_{2 >}CL_{2 >}CO₂ B. NH_{3 >}CO_{2 >}SO_{2 >}CL₂ C. CL_{2 >}SO_{2 >}CO_{2 >}NH₃ D. NH_{3 >}CO₂_>CL_{2 >}SO₂
8	The relation ships b/w volume of given amount of gas and prevailing conditions of temperature and pressure are :	A. Charles's law B. Graham's law C. Boyle's law D. Gas law
9	If absolute temperature of a gas is doubled and the pressure is reduced to one half, the volume of gas will :	A. remain unchanged B. increase four times C. reduce to 1/4 D. be doubled
10	All gases can be compressed by :	A. Keeping constant pressure B. Decreasing pressure C. Increasing pressure D. None of the above

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