# Mass Transfer Questions and Answers – Gas-Absorption Principle

This set of Mass Transfer Multiple Choice Questions & Answers (MCQs) focuses on “Gas-Absorption Principle”.

1. Gas absorption is the process of transferring solute component from liquid solvent to gas mixture.
a) True
b) False

Explanation: Solute transfer from liquid to gas is known as stripping or desorption. The solute transfer of gas to liquid is known as Absorption.

2. The equilibrium characteristics of the solubility of a gas in liquid helps to determine the
a) Rate
b) Concentration
c) Time
d) No existence of equilibrium characteristics

Explanation: The equilibrium diagram helps to determine the flux with the help of mass transfer co-efficient and concentration gradient.

3. Solubility of a gas increases with increase in temperature.
a) True
b) False

Explanation: As per the equilibrium solubility curve, if the temperature increases partial pressure increases resulting in decreasing solubility.

4. Which of the following is not an example of ideal solution?
a) Solution of benzene in toluene
b) Solution of ethyl and propyl alcohol
c) Paraffin hydrocarbon gas in paraffin oil
d) Solution of isobutane and olefins

Explanation: Only adjacent homologous series falls in ideal solution category. Here, isobutane is an alkane and olefins are alkenes.

5. According to Raoult’s law, for a pure component solution the partial pressure is equals to
a) Total pressure
b) Vapour pressure
c) Atmospheric pressure
d) Mole fraction of respective phase

Explanation: Generally, Raoult’s law states that equilibrium partial pressure of a component at certain conditions equals the product of the mole fraction and the vapour pressure. For a pure component (i.e.) mole fraction equals one.
Therefore, the partial pressure equals vapour pressure.

6. According to Hendry’s law,
a) Y=(p/P)
b) Y=(p* P)
c) p=(Y/P)
d) p=(Y*P)

Explanation: For a straight line Y=m*x, the law proved by Hendry. (i.e.) Y=(y/P) =m*x.
Where, Y=equilibrium mole fraction in vapour
pA= partial pressure
P= Total pressure.

7. Match the following
1) Hendry’s law – a)Ideal solution
2) Dalton’s law – b)Non- Ideal solution
3) Raoult’s law -c)Sum of partial pressure
a) 1- (b), 2-(c),3-(a)
b) 1-(a),2-(b),3-(c)
c) 1-(c),2-(b),3-(a)
d) 1-(a),2-(c),3-(b)

Explanation: Dalton proved a generalized equation states that total pressure is equals to the sum of the partial pressure of the components. Raoult’s law is applicable for only ideal solution since the partial pressure is equals to the product of mole fraction and the vapour pressure.

8. Find the false statement for the better choice of the absorbent.
a) Gas solubility should be high
b) Vapour pressure should be low
c) Viscosity should be high
d) Low freezing point

Explanation: For a better choice of absorbent, the viscosity should be low to get the rapid absorption rates, low pressure drops in absorption tower.

9. Find the most common example for absorption.
a) Ammonia and air in solvent water
b) Ammonia and Carbon dioxide in solvent water
c) Methane and air in solvent water
d) Methane and Carbon dioxide in solvent water

Explanation: Since air won’t dissolve in water the affinity of nitrogen towards the water will be more which converts ammonia into ammonium solution. But in other options, the hydrocarbons easily dissolves in polar solvents.

10. Find the improper characteristic of ideal solution.
a) The average intermolecular force of attraction and repulsion are unchanged on mixing
b) Volume varies linearly with compositions
c) No evolution of heat
d) The total partial pressure varies linearly with compositions

Explanation: Because the vapour pressure only varies linearly with compositions.

Sanfoundry Global Education & Learning Series – Mass Transfer.

To practice all areas of Mass Transfer, here is complete set of 1000+ Multiple Choice Questions and Answers