ECAT Pre Engineering Chemistry Chapter 3 MCQ Test With Answer

Question # 1

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 # 2

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 # 3

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 # 4

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 # 5

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 # 6

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 # 7

Cooling happens under the Joule Thomson Effect due to sudden

Contraction A
Absorption B
Expansion C
All of above 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

Boyle's law is represented as :

P∞ 1/T
A
V and 1/P B
P∞P C
P∞1/P D

Question # 10

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 # 11

Liquids are less common than

Solids A
Plasmas B
Gases C
All of above D

Question # 12

In solids, the temperature of is the measure of

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

Question # 13

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 # 14

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 # 15

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 # 16

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 # 17

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 # 18

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 # 19

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

Isobaric A
Isothermal B
Isotherm C
None of above D

Question # 20

Cooling happens under the Joule Thomson Effect due to sudden :

Contraction A
Absortption B
Expansion C
All of above 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

The intramolecular forces in gases are

Weak A
Normal B
Very weak C
Strong D

Question # 23

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 # 24

The intramolecular force in gases are :

Weak A
Normal B
Very weak C
Strong D

Question # 25

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 # 26

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 # 27

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 # 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

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 # 30

Gases show uniform behaviour towards their

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

Sr.#	Question	Answer
1	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.
2	A graph between P and 1/V at constant temperature and number moles of a gas meets the	A. y-axis B. x-axis C. origin D. none of above
3	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
4	All gases can be compressed by :	A. Keeping constant pressure B. Decreasing pressure C. Increasing pressure D. None of the above
5	In gases and liquids, temperature is the measure of	A. Average translational kinetic energies of molecules B. Average vibrational kinetic energies of molecules C. Average rotational kinetic energies of molecules D. None of above
6	If absolute temperature of a gas is doubled and the pressure is reduced to one half, the volume of the gas will be	A. Remain unchanged B. Doubled C. Reduced D. Increased four times
7	The density of a gas is directly proportional to pressure, inversely proportional to temperature and directly proportional to	A. Viscosity B. Molar mass C. Momentum D. All of above
8	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
9	The intramolecular forces in gases are	A. Weak B. Normal C. Very weak D. Strong
10	Liquids are less common than	A. Solids B. Plasmas C. Gases D. All of above

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