250+ TOP MCQs on Diffusivity at 25 Degree Celsius and 1 atm Pressure and Answers

Mass Transfer Assessment Questions on “Diffusivity At 25 Degree Celsius And 1 atm Pressure”.

1. What is the value of diffusivity for ammonia?
a) 0.26
b) 0.27
c) 0.28
d) 0.29
Answer: c
Clarification: Ammonia is a colorless gas and it boils at a pressure of one atmosphere. It is easily liquefied due to the strong hydrogen bonding. Its unit is cm²/s.

2. Which one is having the highest value of diffusivity?
a) Hydrogen
b) Oxygen
c) Water
d) Methanol
Answer: a
Clarification: Thermal diffusivity of hydrogen is 0.410 while that of oxygen, water and methanol are 0.206, 0.259 and .0159 respectively. Its unit is cm ²/s.

3. What is the value of diffusivity for hydrogen?
a) 0.210
b) 0.310
c) 0.410
d) 0.510
Answer: c
Clarification: It is highly flammable and will burn in air at a very wide range of concentrations. It reacts with every oxidizing agent. Its unit is cm ²/s.

4. Which one is having the lowest value of diffusivity?
a) Acetic acid
b) Oxygen
c) Benzene
d) Toluene
Answer: d
Clarification: Thermal diffusivity of toluene is 0.084 while that of acetic acid, oxygen and benzene are 0.133, 0.206 and 0.081 respectively. Its unit is cm ²/s.

5. What is the value of diffusivity for water?
a) 0.233
b) 0.256
c) 0.276
d) 0.298
Answer: b
Clarification: It is transparent in the visible electromagnetic spectrum. It has high specific heat capacity and latent heat of vaporisation. Its unit is cm ²/s.

6. Which one is having the highest value of diffusivity?
a) Water
b) Oxygen
c) Hydrogen
d) Carbon dioxide
Answer: a
Clarification: Thermal diffusivity of water is 0.256 while that of oxygen, hydrogen and carbon dioxide are 0.206, 0.210 and 0.164 respectively. Its unit is cm²/s.

7. What is the value of diffusivity for ethyl alcohol?
a) 0.117
b) 0.118
c) 0.119
d) 0.120
Answer: c
Clarification: There are extensive hydrogen bonding between its molecules. Its unit is cm²/s.

8. Which one is having the lowest value of diffusivity?
a) Glucose
b) Urea
c) Ethanol
d) Oxygen
Answer: a
Clarification: Thermal diffusivity of glucose is 0.60 while that of urea, oxygen and ethanol are 8.06, 1.80 and 1.00 respectively. Its unit is cm² /s.

9. What is the value of diffusivity for benzene?
a) 0.055
b) 0.066
c) 0.077
d) 0.088
Answer: d
Clarification: It is having higher diffusivity so they diffuse faster into each other. Its unit is cm²/s.

10. Which one is having the highest value of diffusivity?
a) Ammonia
b) Urea
c) Glucose
d) Ethanol
Answer: b
Clarification: Thermal diffusivity of urea is 8.06 while that of ammonia, glucose and ethanol are 1.76, 0.60 and 1.00 respectively. Its unit is cm ²/s.

Mass Transfer for assessment test,