ECAT Pre Engineering Chemistry Chapter 3 MCQ Test With Answer

Question # 1

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

Isobaric A
Isothermal B
Isotherm C
None of above D

Question # 2

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 # 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

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 # 5

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 # 6

Which of the following is the simplest form of matter?

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

Question # 7

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 # 8

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 # 9

All gases can be compressed by

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

Question # 10

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 # 11

The intramolecular forces in gases are

Weak A
Normal B
Very weak C
Strong D

Question # 12

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 # 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 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

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 # 16

All gases can be compressed by :

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

Question # 17

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

Evaportation A
Effusion B
Conduction C
Diffusion D

Question # 18

A graph b/w P and 1/V at constant temperature and number of moles is parallel to :

Y-axis A
Z-axis B
X-axis C
None of above D

Question # 19

The density of a gas is directly proportional to pressure, inversely proportional to temperature and directly proportional to

Viscosity A
Molar mass B
Momentum C
All of above D

Question # 20

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 # 21

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 # 22

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 # 23

Absolute temperature of a gas is proportional to

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

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

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 # 27

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 # 28

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 # 29

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 # 30

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

Sr.#	Question	Answer
1	Which Statement about gases is not correct?	A. They spread throughout the vessel B. Pressure is due to collision C. There are larger spaces between the molecules D. Molecules are arranged regularly
2	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.
3	In gases and liquids, temperature is the measure of :	A. Average transnational kinetic energies of molecules. B. Average vibrational kinetic energies of molecules. C. Average rotational kinetic energies of molecules. D. None of above
4	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.
5	The product of pressure and volume remains constant when temperature and quantity of gas is	A. zero B. variable C. kept constant D. None of these
6	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
7	Liquids are less common than	A. Solids B. Plasmas C. Gases D. All of above
8	Absolute temperature of a gas is proportional to	A. Rotational kinetic energy B. Translational kinetic energy C. Vibrational kinetic energy D. Potential energy
9	For a gas obeying Boyle's law if pressure is doubled, the volume becomes	A. Remains constant B. Double C. One half D. None of above
10	The intramolecular force in gases are :	A. Weak B. Normal C. Very weak D. Strong

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