Chemical Engineering Thermodynamics MCQs

Question 1

Which of the following is not a common refrigerant?

Accepted Answer

Ethylene

Answer

Freon-12

Answer

Ammonia

Answer

Carbon dioxide

Question 2

Which of the following is not a reversible process ?

Accepted Answer

Solution of NaCl in water at 50°C

Answer

Expansion of an ideal gas against constant pressure

Answer

Atmospheric pressure vaporisation of water at 100°C

Answer

None of these

Question 3

For spontaneous changes in an isolated system (S = entropy)

Accepted Answer

Ds > 0

Answer

Ds = 0

Answer

Ds <0

Answer

Ds = Constant

Question 4

A gas performs the maximum work, when it expands

Accepted Answer

Isobarically

Answer

Non-uniformly

Answer

Adiabatically

Answer

Isothermally

Question 5

Degree of freedom of a system consisting of a gaseous mixture of H2 and NH3 will be

Accepted Answer

3

Answer

0

Answer

1

Answer

2

Question 6

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system

Accepted Answer

U and S both decreases

Answer

Its internal energy (U) decreases and its entropy (S) increases

Answer

U decreases but S is constant

Answer

U is constant but S decreases

Question 7

The expression for entropy change given by, $$\Delta S = - nRln\left( {\frac{{{P_2}}}{{{P_1}}}} \right),$$ holds good for

Accepted Answer

Reversible isothermal volume change

Answer

Expansion of a real gas

Answer

Heating of an ideal gas

Answer

Cooling of a real gas

Question 8

For any system, what is the minimum number of degrees of freedom?

Accepted Answer

0

Answer

1

Answer

2

Answer

3

Question 9

Which of the following is not a unit of the equilibrium constant Kp? (where, Δx = number of moles of products number of moles of reactants)

Accepted Answer

(atm)Δx2, when Δx > 0

Answer

(atm)Δx, when Δx is negative

Answer

(atm)Δx, when Δx is positive

Answer

Dimensionless, when Δx = 0