ECAT Pre Engineering Chemistry Chapter 3 MCQ Test With Answer

Question # 1

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

Question # 2

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 # 3

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 # 4

Cooling happens under the Joule Thomson Effect due to sudden :

Contraction A
Absortption B
Expansion C
All of above D

Question # 5

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 # 6

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 # 7

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 # 8

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 # 9

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

Evaportation A
Effusion B
Conduction C
Diffusion D

Question # 10

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 # 11

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 # 12

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 # 13

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 # 14

All gases can be compressed by

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

Question # 15

In solids, the temperature of is the measure of

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

Question # 16

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 # 17

All gases can be compressed by :

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

Question # 18

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 # 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

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 # 21

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 # 22

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 # 23

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 # 24

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 # 25

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 # 26

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 # 27

The molar value of CO₂is maximum at :

STP A
127°C and 1 atm B
0°C and 2 atm C
273°C and 2 atm D

Question # 28

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 # 29

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 # 30

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

Sr.#	Question	Answer
1	Equal masses of methane and oxygen are mixed in an empty container at 25°CThe fraction of total pressure exerted by oxygen is :	A. 1/2 B. 8/9 C. 1/9 D. 16/17
2	Cooling happens under the Joule Thomson Effect due to sudden :	A. Contraction B. Absortption C. Expansion D. All of above
3	For a gas obeying Boyle's law if pressure is doubled, the volume becomes :	A. Remain constant B. Double C. One half D. None of above
4	A graph between P and PV at constant temperature and number of mole is parallel to	A. y axis B. z axis C. x axis D. pressure axis
5	According to Boyle's law. which parameters give a straight line parallel to x-axis, when we plot a graph between	A. V and T B. P and V C. P and 1/V D. P and PV
6	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
7	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
8	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
9	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.
10	The density of a gas is directly and volume at constant temperature for a gas is	A. Isobaric B. Isothermal C. Isotherm D. None of above

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