MCQOPTIONS
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MCQOPTIONS
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 | |
| 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 | |
| 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. | |
| 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 | |
| 5. |
At the triple point, l(sublimation) = l(vaporization) – l(fusion). |
| A. | true |
| B. | false |
| Answer» C. | |
| 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 | |
| 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 | |
| 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.$# |
| A. | 0.0058 kPa |
| B. | 0.0098 kPa |
| C. | 0.0068 kPa |
| D. | 0.0088 kPa |
| Answer» C. 0.0068 kPa | |
| 9. |
Latent_heat_of_sublimation_is_given_by$ |
| 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. | |
| 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 | |
| 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 | |
| 12. |
At the triple point, l(sublimation) = l(vaporization) – l(fusion)?# |
| A. | true |
| B. | false |
| Answer» C. | |
| 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. | |
| 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 | |
| 15. |
The vapour pressure curve is of the form ln(p) = A + B/T + C*lnT + DT. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 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 | |
| 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) | |
| 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 | |
| 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 | |