ECAT Pre Engineering Chemistry Chapter 3 MCQ Test With Answer

Question # 1

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 # 2

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 # 3

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 # 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

Which of the following is the simplest form of matter?

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

Question # 6

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 # 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

Absolute temperature of a gas is proportional to

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

Question # 9

Gases shows uniform behavior toward their :

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

Question # 10

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

Evaportation A
Effusion B
Conduction C
Diffusion D

Question # 11

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 # 12

All gases can be compressed by :

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

Question # 13

Gases show uniform behaviour towards their

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

Question # 14

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 # 15

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 # 16

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 # 17

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 # 18

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 # 19

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 # 20

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 # 21

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 # 22

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 # 23

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 # 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

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 # 26

Liquids are less common than :

Solids A
Plasmas B
Gases C
All of above D

Question # 27

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 # 28

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 # 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

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

Sr.#	Question	Answer
1	The highest temperature at which a substance can exist as a liquid is called its	A. Critical temperature B. Zero temperature C. Absolute temperature D. None of above
2	The deviation of a gas from ideal behavior is maximum at :	A. -10°C and 5.0 atm B. -10°C and 2.0 atm C. 100°C and 2.0 atm D. 0°C and 2.0 atm
3	Liquids are less common than	A. Solids B. Plasmas C. Gases D. All of above
4	Which of the following is the simplest form of matter?	A. Gaseous state B. Liquid State C. Solid State D. All of above
5	The graph between pressure and volume at constant temperature for a gas is	A. Isobaric B. Isothermal C. Isotherm D. None of above
6	Keeping the temperature constant, if the gas is expanded	A. kinetic energy of molecules will increase B. Number of gas molecules increases C. Temperature will increases D. Pressure will decrease
7	Gases show uniform behaviour towards their	A. Internal conditions B. External conditions C. Internal and external conditions D. None of above
8	Boyle's law does not fall even	A. Temperature is extremely high B. Pressure is extremely high C. Mixture of gases is taken D. all of above
9	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
10	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

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