Explore topic-wise MCQs in Thermodynamics.

This section includes 19 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.

1.

Ice (solid water) at −3°C and 100 kPa, is compressed isothermally until it becomes liquid. Find the required pressure.

A. 20461 kPa
B. 30461 kPa
C. 40461 kPa
D. 50461 kPa
Answer» D. 50461 kPa
Discussion
2.

An application requires R-12 at −140°C. The triple-point temperature is −157°C. Find the pressure of the saturated vapour at the required condition.

A. 0.0058 kPa
B. 0.0098 kPa
C. 0.0068 kPa
D. 0.0088 kPa
Answer» C. 0.0068 kPa
Discussion
3.

Latent heat of sublimation is given by

A. l(sublimation) = -2.303*(R)*(d(1/T)/d(log p ))
B. l(sublimation) = +2.303*(R)*(d(log p )/d(1/T))
C. l(sublimation) = +2.303*(R)*(d(1/T)/d(log p ))
D. l(sublimation) = -2.303*(R)*(d(log p )/d(1/T))
Answer» E.
Discussion
4.

The slope of sublimation curve is ____ the slope of the vaporization curve at triple point.

A. equal to
B. less than
C. greater than
D. none of the mentioned
Answer» D. none of the mentioned
Discussion
5.

At the triple point, l(sublimation) = l(vaporization) – l(fusion).

A. true
B. false
Answer» C.
Discussion
6.

According to Trouton’s rule, the ratio of latent heat of vaporization to the boiling point at 1.013 bar is

A. 77 kJ/kgmol K
B. 88 kJ/kgmol K
C. 99 kJ/kgmol K
D. 100 kJ/kgmol K
Answer» C. 99 kJ/kgmol K
Discussion
7.

THE_SLOPE_OF_SUBLIMATION_CURVE_IS______THE_SLOPE_OF_THE_VAPORIZATION_CURVE_AT_TRIPLE_POINT.?$

A. equal to
B. less than
C. greater than
D. none of the mentioned
Answer» D. none of the mentioned
Discussion
8.

An application requires R-12 at −140°C. The triple-point temperature is −157°C. Find the pressure of the saturated vapour at the required condition.$#

A. 0.0058 kPa
B. 0.0098 kPa
C. 0.0068 kPa
D. 0.0088 kPa
Answer» C. 0.0068 kPa
Discussion
9.

Latent_heat_of_sublimation_is_given_by$

A. l(sublimation) = -2.303*(R)*(d(1/T)/d(log p ))
B. l(sublimation) = +2.303*(R)*(d(log p )/d(1/T))
C. l(sublimation) = +2.303*(R)*(d(1/T)/d(log p ))
D. l(sublimation) = -2.303*(R)*(d(log p )/d(1/T))
Answer» E.
Discussion
10.

Estimate the freezing temperature of liquid water at a pressure of 30 MPa.

A. -2.2°C
B. 0°C
C. -0.2°C
D. -1.2°C
Answer» B. 0¬¨¬®‚Äö√†√ªC
Discussion
11.

Ice (solid water) at −3°C and 100 kPa, is compressed isothermally until it becomes liquid. Find the required pressure.$

A. 20461 kPa
B. 30461 kPa
C. 40461 kPa
D. 50461 kPa
Answer» D. 50461 kPa
Discussion
12.

At the triple point, l(sublimation) = l(vaporization) – l(fusion)?#

A. true
B. false
Answer» C.
Discussion
13.

The vapour pressure p in kPa at temperature T can be given by the relation

A. p = 101.325 exp (88/R)(1+T/Tb)
B. p = 101.325 exp (88/R)(1+Tb/T)
C. p = 101.325 exp (88/R)(1-T/Tb)
D. p = 101.325 exp (88/R)(1-Tb/T)
Answer» E.
Discussion
14.

According to Trouton’s rule, the ratio of latent heat of vaporization to the boiling point at 1.013 bar is$

A. 77 kJ/kgmol K
B. 88 kJ/kgmol K
C. 99 kJ/kgmol K
D. 100 kJ/kgmol K
Answer» C. 99 kJ/kgmol K
Discussion
15.

The vapour pressure curve is of the form ln(p) = A + B/T + C*lnT + DT.

A. true
B. false
Answer» B. false
Discussion
16.

Water ____ on melting and has the fusion curve with a ____ slope.

A. contracts, negative
B. contracts, positive
C. expands, negative
D. expands, positive
Answer» B. contracts, positive
Discussion
17.

The Clausius-Clapeyron equation is given by

A. dp/dT = l / T(vf+vi)
B. dp/dT = l / T(vf-vi)
C. dT/dp = l / T(vf+vi)
D. dT/dp = l / T(vf-vi)
Answer» C. dT/dp = l / T(vf+vi)
Discussion
18.

Which of the following requirement is satisfied by a phase change of the first order?

A. there are changes of volume and entropy
B. the first-order derivative of the Gibbs function changes discontinuously
C. both of the mentioned
D. none of the mentioned
Answer» D. none of the mentioned
Discussion
19.

During phase transitions like vaporization, melting and sublimation

A. pressure and temperature remains constant
B. volume and entropy changes
C. both of the mentioned
D. none of the mentioned
Answer» D. none of the mentioned
Discussion