Basic Chemical Engineering Multiple Choice Questions & Answers (MCQs) on “Ideal Reversible Processes”.
1. How long would it take for a reversible process to complete?
a) Instant
b) Infinite
c) Depends on the process
d) None of the mentioned
Answer: b
Clarification: It takes infinite time for a reversible process to complete.
2. How long would it take for an irreversible process to complete?
a) Instant
b) Finite
c) Infinite
d) Cannot say
Answer: b
Clarification: It takes a finite time for an irreversible process to complete.
3. Reversible process can be reversed by differential change in which of the following?
a) Temperature
b) Pressure
c) Volume
d) All of the mentioned
Answer: d
Clarification: Differential change in driving potential (dP, dV, dT, etc) can reverse a reversible process.
4. Which of the following a reversible process will involve?
a) Dissipative effects
b) Friction
c) Equilibrium transfer of energy
d) None of the mentioned
Answer: c
Clarification: Reversible process involves equilibrium transfer of energy.
5. Which of the following does both of the reversible and irreversible processes involve?
a) Increase molecular disorder
b) Dissipative effects
c) Friction
d) All of the mentioned
Answer: a
Clarification: Both reversible and irreversible processes increases molecular disorder.
6. Free expansion of gas with frictionless piston is an example which process?
a) Reversible
b) Irreversible
c) Cannot say
d) None of the mentioned
Answer: a
Clarification: Free expansion of gas is reversible process.
7. Free expansion of gas against piston having friction is an example of which process?
a) Reversible
b) Irreversible
c) Cannot say
d) None of the mentioned
Answer: b
Clarification: Free expansion of gas against piston having friction is irreversible process.
8. Mixing of dissimilar substances is an example of which process?
a) Reversible
b) Irreversible
c) Cannot say
d) None of the mentioned
Answer: b
Clarification: Mixing of dissimilar substances is an irreversible process.
9. Change in phase is an example of which process?
a) Reversible
b) Irreversible
c) Cannot say
d) None of the mentioned
Answer: b
Clarification: Change in phase is an irreversible process.
10. Fluid flow through pipe is an example of which process?
a) Reversible
b) Irreversible
c) Cannot say
d) None of the mentioned
Answer: b
Clarification: Fluid flow through pipe is an irreversible process.
11. What is the work done by saturated water which evaporates to 10 kPa atmosphere to form 1 m3 of water vapor?
a) 1 kJ
b) -1 kJ
c) 10 kJ
d) -10 kJ
Answer: d
Clarification: Work done = -p∆V = -10*1 = -10 kJ.
12. What is the work done by saturated water which evaporates to 20 kPa atmosphere to form 1.5 m3 of water vapor?
a) 20 kJ
b) -20 kJ
c) 30 kJ
d) -30 kJ
Answer: d
Clarification: Work done = -p∆V = -20*1.5 = -30 kJ.
13. What is the work done by saturated water which evaporates to 1 kPa atmosphere to form 2 m3 of water vapor?
a) -2 kJ
b) 2 kJ
c) -1 kJ
d) 1 kJ
Answer: a
Clarification: Work done = -p∆V = -1*2 = -2 kJ.
14. What is the work done by 0.1 m3 saturated ethanol which evaporates to 10 kPa atmosphere to form 1 m3 of water vapor?
a) 9 kJ
b) -9 kJ
c) 10 kJ
d) -10 kJ
Answer: b
Clarification: Work done = -p∆V = -10*(1 – 0.1) = -9 kJ.
15. What is the work done by 0.5 m3 saturated ethanol which evaporates to 20 kPa atmosphere to form 2 m3 of water vapor?
a) 20 kJ
b) -20 kJ
c) 30 kJ
d) -30 kJ
Answer: d
Clarification: Work done = -p∆V = -20*(2 – 0.5) = -30 kJ.