NEET Chemistry States Of Matter MCQs Set A

Question: A sample of gas occupies 10 L under a pressure of 1 atm. What will be its volume if the pressure is increased to 2 atm? Assuming that temperature of the gas sample does not change

• a) 2 L
• b) 5 L
• c) 10 L
• d) 1 L

Answer: 5 L

Question:  A gas at a pressure of 5 atm is heated from 0° to 546°C and simultaneously compressed to 1/3 rd of its original volume. Hence final pressure is

• a) 10 atm
• b) 45 atm
• c) 30 atm
• d) 5 atm

Answer: 45 atm

Question: How much should the pressure be increased in order to decrease the volume of a gas by 5% at a constant temperature?

• a) 5%
• b) 5.26%
• c) 10%
• d) 4.26%

Answer: 5.26%

Question:  When the temperature is raised through 1°C the volume is increased by 1/273 th times of the original volume. This is

• a) Boyle's Law
• b) Charles' Law
• c) Avogadro Law
• d) Graham's Law

Answer: Charles' Law

Question: Which curve shows Charles’ law?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  I, II, III are three isotherms respectively at T₁, T₂, T₃ . Temperature will be in order

• a) T₁= T₂= T₃
• b) T₁< T₂< T₃
• c) T₁> T₂> T₃
• d) T₁> T₂= T₃

Answer:  T₁> T₂> T₃

Question:  To what temperature must a neon gas sample be heated to double its pressure if the initial volume of gas at 75°C is decreased by 15.0%?

• a) 592 K
• b) 492 K
• c) 542 K
• d) 642 K

Answer: 592 K

Question:  When a gas filled in a closed vessel is heated through 1°C, its pressure is increased by 0.4%. The initial temperature of the gas was

• a) 250 K
• b) 2500 K
• c) 250°C 
• d) 25°C

Answer: 250 K

Question: “One gram molecules of a gas at N.T.P. occupies 22.4 litres”. This fact was derived from

• a) Dalton’s theory
• b) Avogadro’s hypothesis
• c) Berzelius hypothesis
• d) Law of gaseous volume

Answer: Avogadro’s hypothesis

Question:  A sample of gas at 1.2 atm and 27°C is heated at constant pressure to 57°C. Its final volume is found to be 4.75 litres. What was its original volume?

• a) 4.32 litres
• b) 5.02 litres
• c) 4.22 litres
• d) None of these

Answer: 4.32 litres

Question:  If the density of a certain gas at 30°C and 768 torr is 1.35 kg/m3 its density at STP would be

• a) 1.48 kg/m³ 
• b) 1.58 kg/m³ 
• c) 1.25 kg/m³
• d) 1.4 kg/m³

Answer:  1.48 kg/m³ 

Question:  A vessel has 6 g of oxygen at a pressure P and temperature 400 K. A small hole is made in it so that O₂ leaks out. How much O₂ leaks out if the pressure is P/2 and temperature 300 K?

• a) 5 g
• b) 4 g
• c) 2 g
• d) 3 g

Answer: 2 g

Question:   What percent of a sample of nitrogen must be allowed to escape if its temperature, pressure and volume are to be changed from 220°C, 3 atm and 1.65 litre to 110°C, 0.7 atm and 1.00 litre respectively?

• a) 81.8%
• b) 71.8%
• c) 76.8%
• d) 86.8%

Answer: 81.8%

Question:  2 g of gas A introduced in a evacuated flask at 25°C. The pressure of the gas is 1 atm. Now 3 g of another gas B is introduced in the same flask so total pressure becomes 1.5 atm. The ratio of molecular mass of A and B is

• a) 3/1
• b) 1/3
• c) 1/4
• d) 2/3

Answer: 1/3

Question: Which mixture of gases at room temperature does not obey Dalton's law of partial pressure?

• a) NO₂ and O₂   
• b) NH₃ and HCl
• c) CO and CO₂
• d) SO₂ and SO₃

Answer:  NH₃ and HCl

Question: The two bulbs of volume 5 litre and 10 litre containing an ideal gas at 9 atm and 6 atm respectively are connected. What is the final pressure in the two bulbs if the temperature remains constant?

• a) 15 atm
• b) 7 atm
• c) 12 atm
• d) 21 atm

Answer: 7 atm

Question: Two non-reactive gases A and B are present in a container with partial pressures 200 and 180 mm of Hg. When a third non-reactive gas C is added then total pressure becomes 1 atm then mole fraction of C will be

• a) 0.75
• b) 0.5
• c) 0.25
• d) Cannot be calculated

Answer: 0.5

Question: The density of neon will be highest at

• a) STP
• b) 0°C and 2 atm 
• c) 273°C and 1 atm 
• d) 273°C and 2 atm

Answer:  0°C and 2 atm 

Question: Which of the following relation is correct for an ideal gas?

• a)

  

• b)

  

• c)

  

• d) All of these

Answer:

Question: A bottle of dry ammonia and a bottle of dry hydrogen chloride connected through a long tube are opened simultaneously at both ends, the white ammonium chloride ring first formed will be

• a) At the centre of the tube
• b) Near the hydrogen chloride bottle
• c) Near the ammonia bottle
• d) Throughout the length of the tube

Answer: Near the hydrogen chloride bottle

Question: The rates of diffusion of gases A and B of molecular weights 100 and 81 respectively are in the ratio of

• a) 9 : 10
• b) 10 : 9
• c) 100 : 18
• d) 81 : 100

Answer: 9 : 10

More Questions........................................................

Question:  100 mL of O₂ gas diffuses in 10 s. 100 mL of gas 'X' diffuses in 't' sec. Gas 'X' and time 't' can be

• a) H₂, 2.5 s
• b) SO₂, 16 s
• c) CO, 10 s
• d) He, 4 s

Answer:  H₂, 2.5 s

Question: Pressure exerted by a perfect gas is equal to

• a) Mean kinetic energy per unit volume
• b) Half of the mean kinetic energy per unit volume
• c) Two thirds of mean kinetic energy per unit volume
• d) One third of mean kinetic energy per unit volume

Answer: Two thirds of mean kinetic energy per unit volume

Question: When there can be more deviation in the behaviour of a gas from the ideal gas equation PV = nRT

• a) At high temperature and low pressure
• b) At low temperature and high pressure
• c) At high temperature and high pressure
• d) At low temperature and low pressure

Answer: At low temperature and high pressure

Question: In van der Waal’s equation of state for a non-ideal gas, the term that accounts for intermolecular forces is

• a) V – 1
• b) RT
• c)

  

• d) (RT)^–1

Answer:

Question: van der Waal’s constant ‘a’ has the dimensions of

• a) mol L^–1 
• b) atm L² mol^–2 
• c) litre mol^–1
• d) atm L mol^–2

Answer:  atm L² mol^–2 

Question: van der Waal found that two assumptions made by kinetic theory of gases were wrong, one of them is that gas molecules are

• a) Very large
• b) Compressible
• c) Point particles without significant volume
• d) Spherical

Answer: Point particles without significant volume

Question: Which one is correct relation for 1 mole of real gases?

• a)

  

• b)

  

• c)

  

• d) Both (1) & (2)

Answer: Both (1) & (2)

Question: For a real gas, Z shows

• a) Z < 1, gas is less compressible
• b) Z > 1, gas is more compressible
• c) Z = ∞, for an ideal gas 
• d) PV ≠ nRT, for real gas

Answer:  PV ≠ nRT, for real gas

Question: The compressibility factor ‘Z’ for the gas is given by

• a) Z = PV_obs
• b)

  

• c) Z = nRT
• d) Z = PV.nRT

Answer:

Question: Which of the following gas always shows positive deviation from ideal gas behaviour?

• a) H₂
• b) CO₂
• c) NH₃  
• d) CH₄

Answer:  H₂

Question: For non-zero value of force of attraction between gas molecules, gas equation will be

• a)

  

• b) PV = nRT + nbP
• c)

  

• d) PV = nRT

Answer:

Question:  What is the ratio of the average molecular kinetic energy of UF₆ to that of H₂ both at 300 K?

• a) 1 : 1
• b) 349 : 2
• c) 2 : 349
• d) None of these

Answer: 1 : 1

Question: If pressure of a fixed quantity of a gas is increased 4 times keeping the temperature constant, the r.m.s. velocity will be

• a) 4 times
• b) 2 times
• c) Same
• d) 1/2 times

Answer: Same

Question:  The total kinetic energy in joules of the molecules in 8 g of methane at 27°C is

• a) 3741.30 J
• b) 935.3J
• c) 1870.65 J
• d) 700 J

Answer: 1870.65 J

Question:  At what temperature the RMS velocity of oxygen will be same as that of methane at 27°C?

• a) 54°C 
• b) 327 K
• c) 600 K
• d) 573 K

Answer: 600 K

Question:  The temperature at which the root mean square velocity of SO₂ molecules is the same as that of O₂ at 27°C is

• a) 600°C 
• b) 300°C 
• c) 327°C
• d) 27°C

Answer:  327°C

Question:  The average velocity of an ideal gas molecule at 27°C is 0.3 m/s. The average velocity at 927°C will be

• a) 0.6 m/s
• b) 0.3 m/s
• c) 0.9 m/s
• d) 3.0 m/s

Answer: 0.6 m/s

Question: At what temperature will the total KE of 0.3 mol of He be the same as the total KE of 0.4 mol of Ar at 400 K?

• a) 533 K
• b) 400 K
• c) 346 K
• d) 300 K

Answer: 533 K

Question: The time taken for a certain volume of gas to diffuse through a small hole was 2 min. Under similar conditions an equal volume of oxygen took 5.65 minute to pass. The molecular mass of the gas is

• a) 32.0
• b) 11.33
• c) 4.0
• d) 8.0

Answer: 4.0

Question:  The r.m.s. velocity of hydrogen is √7 times the r.m.s. of nitrogen. If T is the temperature of the gas then

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:   Distribution of fraction of molecules with velocity is represented in the figure.

Velocity corresponding to point X is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:   T_c and P_c of a gas are 400 K and 41 atms. respectively. The V_c is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Boyle’s temperature and inversion temperature are related as

• a) T_i= T_b 
• b) 2T = T_b 
• c) T_i= 2T_b 
• d) T_i=√T_b

Answer:  T_i= 2T_b 

Question: The critical temperature of a gas is related to van der Waal’s constants as

• a) T_c= 3b
• b)

  

• c)

  

• d)

  

Answer:

Question:  Boyle’s temperature T_b is equal to 

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The point at which densities of a substance in gaseous as well as in liquid state are same called

• a) Critical point
• b) Isoelectric point
• c) Isotonic point
• d) Ideal point

Answer: Critical point

Question: Which of the following is correct regarding viscosity?

• a) It is internal resistance of a liquid to flow
• b) It increases with increase in temperature of the liquid
• c) Coefficient of viscosity is not represented by ‘η’
• d) All of these

Answer: It is internal resistance of a liquid to flow

Question: If saturated vapours are compressed slowly at constant temperature to half the initial volume, the vapour pressure will

• a) Becomes double
• b) Becomes 4 times
• c) Becomes half
• d) Remains unchanged

Answer: Remains unchanged

Question:  A graph of Maxwell distribution of molecular velocities is plotted below.

Correct order of temperature

• a) T₁> T₂> T₃
• b) T₁< T₂< T₃ 
• c) T₁= T₂> T₃
• d) T₁= T₂= T₃

Answer:  T₁< T₂< T₃ 

Question:  A spherical balloon of 21 cm diameter is to be filled up with H₂ at NTP from a cylinder containing the gas at 20 atm at 27°C. The cylinder can hold 2.82 litre of water. The number of balloons that can be filled up

• a) 11
• b) 10
• c) 8
• d) 1

Answer: 10

Question: What is the correct increasing order of liquefiability of the gas?

• a) H₂< N₂< CH₄< CO₂
• b) H₂< CO₂< CH₄< N₂ 
• c) CO₂< CH₄< N₂< H₂  
• d) CO₂< CH₄< H₂< N₂

Answer:  H₂< N₂< CH₄< CO₂

Question:  4 g argon (Atomic mass = 40) in a bulb at a temperature of T K has a pressure P atm. When the bulb was placed in hot bath at a temperature 50°C more than the first one, 0.8 g of gas had to be removed to get the original pressure. T is equal to

• a) 510 K
• b) 200 K
• c) 100 K
• d) 73 K

Answer: 200 K

Question: A flask containing air (open to atmosphere) is heated from 300 K to 500 K. Then percentage of air escaped to the atmosphere is

• a) 20
• b) 40
• c) 60
• d) 80

Answer: 40

Question:  Equal mass of H₂, He and CH₄ are mixed in empty container at 300 K, when total pressure is 2.6 atm. The partial pressure of H₂ in the mixture is

• a) 0.5 atm
• b) 1.6 atm
• c) 0.8 atm
• d) 0.2 atm

Answer: 1.6 atm

Question:   At STP 16 mL of O₂ diffused through a porous partition in t seconds. What volume of CO₂ will diffuse in the same time and under the same conditions?

• a) 13.65 mL
• b) 10.5 mL
• c) 20.2 mL
• d) 224.8 mL

Answer: 13.65 mL

Question:   The molecular velocities of two gases at the same temperature are u₁ and u₂ and their molar masses are m₁ and m₂ respectively. Which of the following expressions are correct?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Correct statement

• a) At constant temperature, the KE of all the gas molecules is the same
• b) At constant temperature, average KE of gas molecules remain constant but KE of individual molecule may differ
• c) At constant temperature, the KE is greater for heavier gas molecules
• d) At constant temperature, the KE is less for heavier gas molecules

Answer: At constant temperature, average KE of gas molecules remain constant but KE of individual molecule may differ

Question:   Air contains 23% oxygen and 77% nitrogen by weight. The percentage of O₂ by volume is

• a) 28.1
• b) 20.7
• c) 21.8
• d) 23.0

Answer: 20.7

Question: The density of gas A is twice that of gas B at the same temperature. The molecular weight of gas B is thrice that of A. The ratio of pressure acting on A and B will be

• a) 6 : 1
• b) 7 : 8
• c) 2 : 5
• d) 1 : 4

Answer: 6 : 1