MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 91 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Partial molal free energy of an element A in solution is same as its |
| A. | activity |
| B. | chemical potential |
| C. | activity co-efficient |
| D. | fugacity |
| Answer» C. activity co-efficient | |
| 2. |
The unity of Planck\'s constant \'h\' in the equation, E = hv is |
| A. | J.S |
| B. | J/s |
| C. | kmol/J |
| D. | J/kmol |
| Answer» B. J/s | |
| 3. |
In case of steady flow compression polytropic process (PVn = constant), the work done on air is the lowest, when |
| A. | n = 0 |
| B. | n = y = 1.4 |
| C. | n = 1.66 |
| D. | n = 1 |
| Answer» E. | |
| 4. |
C p of a gas at its critical temperature and pressure |
| A. | becomes zero. |
| B. | becomes infinity. |
| C. | equals 1 kcal/kmol °K. |
| D. | equals 0.24 kcal/kmol °K. |
| Answer» C. equals 1 kcal/kmol °K. | |
| 5. |
Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole . °K |
| A. | 0 |
| B. | ? |
| C. | 50 |
| D. | 100 |
| Answer» C. 50 | |
| 6. |
In the decomposition of PCl 5 represented by, PCl 5 PCl 3 + Cl 2 , decrease in the pressure of the system will __________ the degree of dissociation of PCl 5 . |
| A. | increase |
| B. | decrease |
| C. | not alter |
| D. | none of these |
| Answer» B. decrease | |
| 7. |
PV y = constant, holds good for an isentropic process, which is |
| A. | reversible and isothermal. |
| B. | isothermal and irreversible. |
| C. | reversible and adiabatic. |
| D. | adiabatic and irreversible. |
| Answer» D. adiabatic and irreversible. | |
| 8. |
At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole fractions of methanol are 0.1686 and 0.5714 respectively. Activity co-efficient of methanol is |
| A. | 1.572 |
| B. | 1.9398 |
| C. | 3.389 |
| D. | 4.238 |
| Answer» B. 1.9398 | |
| 9. |
As pressure approaches zero, the ratio of fugacity to pressure ( f / P ) for a gas approaches |
| A. | zero |
| B. | unity |
| C. | infinity |
| D. | an indeterminate value |
| Answer» C. infinity | |
| 10. |
Helmholtz free energy ( A ) is defined as |
| A. | A = H - TS |
| B. | A = E - TS |
| C. | A = H + TS |
| D. | none of these |
| Answer» C. A = H + TS | |
| 11. |
If heat contents of CH 4 , C 2 H 4 and C 3 H 8 are -17.9, 12.5 and -24.8 kcal/mole respectively, than ?H for the reaction CH 4 ( g ) + C 2 H 4 ( g ) C 3 H 8 ( g ) will be __________ Kcal. |
| A. | -19.4 |
| B. | -30.2 |
| C. | 55.2 |
| D. | -55.2 |
| Answer» B. -30.2 | |
| 12. |
In the equation, PV n = constant, if the value of n is in between 1 and y ( i . e . C p / C v ), then it represents a reversible __________ process. |
| A. | isometric |
| B. | polytropic |
| C. | isentropic |
| D. | isobaric |
| Answer» C. isentropic | |
| 13. |
Choose the condition that must be specified in order to liquify CO 2 (triple point for CO 2 is - 57°C and 5.2 atm). |
| A. | Pressure must be kept below 5.2 atm. |
| B. | Temperature must be kept above - 57°C. |
| C. | Pressure must be kept below 5.2 atm. and temperature must be kept above 57°C. |
| D. | Pressure and temperature must be kept below 5.2 atm. and - 57°C respectively. |
| Answer» E. | |
| 14. |
The fugacity of a gas in a mixture is equal to the product of its mole fraction and its fugacity in the pure state at the total pressure of the mixture". This is |
| A. | the statement as per Gibbs-Helmholtz |
| B. | called Lewis-Randall rule |
| C. | Henry's law |
| D. | none of these |
| Answer» C. Henry's law | |
| 15. |
A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is ? i y i P = Y i x i f i ° where, ? is a vapor fugacity component, Y i is the liquid activity co-efficient and f i ° is the fugacity of the pure component i. the K i value ( Y i = K i x i ) is therefore, in general a function of |
| A. | temperature only. |
| B. | temperature and pressure only. |
| C. | temperature, pressure and liquid composition x i only. |
| D. | temperature, pressure, liquid composition x i and vapour composition y i . |
| Answer» D. temperature, pressure, liquid composition x i and vapour composition y i . | |
| 16. |
1m 3 of an ideal gas at 500 K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mole . K, the final temperature will be |
| A. | 35 K |
| B. | 174 K |
| C. | 274 K |
| D. | 154 K |
| Answer» D. 154 K | |
| 17. |
For spontaneous changes in an isolated system ( S = entropy) |
| A. | ds = 0 |
| B. | ds <0 |
| C. | ds > 0 |
| D. | ds = Constant |
| Answer» D. ds = Constant | |
| 18. |
The molar excess Gibbs free energy, g E , for a binary liquid mixture at T and P is given by, ( g E / RT ) = A . x 1 . x 2 , where A is a constant. The corresponding equation for ln y 1 , where y 1 is the activity co-efficient of component 1, is |
| A. | A . x 2 2 |
| B. | Ax 1 |
| C. | Ax 2 |
| D. | Ax 1 2 |
| Answer» B. Ax 1 | |
| 19. |
Work done may be calculated by the expression for __________ processes. |
| A. | non-flow reversible |
| B. | adiabatic |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 20. |
Gibbs free energy ( F ) is defined as |
| A. | F = E - TS |
| B. | F = H - TS |
| C. | F = H + TS |
| D. | F = E + TS |
| Answer» C. F = H + TS | |
| 21. |
An ideal monoatomic gas is taken round the cycle ABCDA as shown below in the P-V diagram The work done during the cycle is |
| A. | PV |
| B. | 2 PV |
| C. | PV /2 |
| D. | 0 |
| Answer» B. 2 PV | |
| 22. |
Air enters an adiabatic compressor at 300K. The exit temperature for a compression ratio of 3, assuming air to be an ideal gas ( Y = C p / C v = 7/5) and the process to be reversible, is |
| A. | 300(3 2/7 ) |
| B. | 300(3 3/5 ) |
| C. | 300(33 3/7 ) |
| D. | 300(3 5/7 ) |
| Answer» B. 300(3 3/5 ) | |
| 23. |
Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg . K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is |
| A. | superheated vapour. |
| B. | partially condensed vapour with quality of 0.9. |
| C. | saturated vapour. |
| D. | partially condensed vapour with quality of 0.1. |
| Answer» B. partially condensed vapour with quality of 0.9. | |
| 24. |
High pressure steam is expanded adiabati-cally and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ? H and ? S respectively for this process: |
| A. | ? H = 0 and ? S = 0. |
| B. | ? H ? 0 and ? S = 0. |
| C. | ? H ? 0 and ? S ? 0. |
| D. | ? H = 0 and ? S ? 0. |
| Answer» C. ? H ? 0 and ? S ? 0. | |
| 25. |
In the equation PV n = constant, if the value of n = y = C p / C v , then it represents a reversible __________ process. |
| A. | isothermal |
| B. | adiabatic |
| C. | isentropic |
| D. | polytropic |
| Answer» D. polytropic | |
| 26. |
On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (? P /? V ) s and the slope of the reversible isothermal line (? P /? V ) T are related as (where, y = C p / C v ) |
| A. | (? P /? V ) S = (? P /? V ) T |
| B. | (? P /? V ) S = [(?P/?V) T ] Y |
| C. | (? P /? V ) S = y (? P /? V ) T |
| D. | (? P /? V ) S = 1/ y (? P /? V ) T |
| Answer» D. (? P /? V ) S = 1/ y (? P /? V ) T | |
| 27. |
Degree of freedom of a system consisting of a gaseous mixture of H 2 and NH 3 will be |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» E. | |
| 28. |
The expression, , is for the____of an ideal gas. |
| A. | compressibility |
| B. | work done under adiabatic contition |
| C. | work done under isothermal condition |
| D. | co-efficient of thermal expansion |
| Answer» D. co-efficient of thermal expansion | |
| 29. |
A cylinder contains 640 gm of liquid oxygen. The volume occupied (in litres) by the oxygen, when it is released and brought to standard conditions (0°C, 760 mm Hg) will be __________ litres. |
| A. | 448 |
| B. | 224 |
| C. | 22.4 |
| D. | data insufficient; can't be computed |
| Answer» B. 224 | |
| 30. |
Sublimation temperature of dry ice (solid CO 2 ) is __________ °C. |
| A. | -273 |
| B. | 0 |
| C. | -78 |
| D. | 5 |
| Answer» D. 5 | |
| 31. |
The efficiency of a Carnot heat engine operating between absolute temperatures T 1 and T 2 (when, T 1 > T 2 ) is given by ( T 1 - T 2 )/ T 1 . The co-efficient of performance (C.O.P.) of a Carnot heat pump operating between T 1 and T 2 is given by |
| A. | T 1 /( T 1 - T 2 ) |
| B. | T 2 /( T 1 - T 2 ) |
| C. | T 1 / T 2 |
| D. | T 2 / R 1 |
| Answer» B. T 2 /( T 1 - T 2 ) | |
| 32. |
In the ammonia synthesis reaction, N 2 + 3H 2 2NH 3 + 22.4 kcal, the formation of NH 3 will be favoured by |
| A. | high temperature. |
| B. | low pressure. |
| C. | low temperature only. |
| D. | both low temperature and high pressure. |
| Answer» E. | |
| 33. |
The internal energy of a gas obeying P ( V - b ) RT (where, b is a positive constant and has a constant C v ), depends upon its |
| A. | pressure |
| B. | volume |
| C. | temperature |
| D. | all (a), (b) & (c). |
| Answer» D. all (a), (b) & (c). | |
| 34. |
In which of the following reaction equilibria, the value of equilibrium constant K p will be more than is K c ? |
| A. | 2HI H 2 + I 2 |
| B. | N 2 O 4 2NO 2 |
| C. | 2SO 2 + O 2 2SO 3 |
| D. | none of these |
| Answer» C. 2SO 2 + O 2 2SO 3 | |
| 35. |
For the reversible exothermic reaction, N 2 + 3H 2 2NH 3 , increase of pressure would |
| A. | shift the equilibrium towards right. |
| B. | give higher yield of NH 3 . |
| C. | both (b) and (c). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 36. |
A thermodynamic system is taken from state A to B along ACB and is brought back to A along BDA as shown below in the P - V diagram. The net work done during the complete cycle is given by the area covered by |
| A. | P 1 ACBP 2 P 1 |
| B. | ACBB 1 A 1 A |
| C. | ACBDA |
| D. | ADBB 1 A 1 A |
| Answer» D. ADBB 1 A 1 A | |
| 37. |
C p - C v = R is valid for __________ gases. |
| A. | ideal |
| B. | all |
| C. | very high pressure |
| D. | very low temperature |
| Answer» B. all | |
| 38. |
The reaction A ( l ) R ( g ) is allowed to reach equilibrium conditions in an autoclave. At equilibrium, there are two phases, one a pure liquid phase of A and the other a vapor phase of A , R and S . Initially A alone is present. The number of degrees of freedom are |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 0 |
| Answer» C. 3 | |
| 39. |
In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respetively, the Carnot COP will be |
| A. | 5.2 |
| B. | 6.2 |
| C. | 0.168 |
| D. | data insufficient, can't be found out |
| Answer» B. 6.2 | |
| 40. |
With increase in pressure (above atmospheric pressure), the C p of a gas |
| A. | increases |
| B. | decreases |
| C. | remains unchanged |
| D. | first decreases and then increases |
| Answer» B. decreases | |
| 41. |
For equilibrium process ( i . e . reversible) in an isolated system |
| A. | ds = 0 |
| B. | ds < 0 |
| C. | ds > 0 |
| D. | ds = Constant |
| Answer» B. ds < 0 | |
| 42. |
For the gaseous phase chemical reaction, C 2 H 4 (g) + H 2 O(g) C 2 H 5 OH(g), the equilibrium conversion does not depend on the |
| A. | steam to ethylene ratio. |
| B. | temperature. |
| C. | pressure. |
| D. | none of these. |
| Answer» E. | |
| 43. |
In the equation, PV n = constant, if the value of n = 1, then it represents a reversible __________ process. |
| A. | isothermal |
| B. | isobaric |
| C. | polytropic |
| D. | adiabatic |
| Answer» B. isobaric | |
| 44. |
The equation relating E , P , V and T which is true for all substanes under all conditions is given by .This equation is called the |
| A. | Maxwell's equation. |
| B. | thermodynamic equation of state. |
| C. | equation of state. |
| D. | Redlich-Kwong equation of state. |
| Answer» C. equation of state. | |
| 45. |
Specific __________ does not change during a phase change ( e . g . sublimation, melting, vaporisation etc.). |
| A. | entropy |
| B. | internal energy |
| C. | enthalpy |
| D. | Gibbs free energy |
| Answer» E. | |
| 46. |
C v for an ideal gas |
| A. | does not depend upon temperature. |
| B. | is independent of pressure only. |
| C. | is independent of volume only. |
| D. | is independent of both pressure and volume. |
| Answer» E. | |
| 47. |
The equation, C p - C v = R , is true for __________ gas. |
| A. | no |
| B. | any real |
| C. | only ideal |
| D. | both (b) and (c) |
| Answer» D. both (b) and (c) | |
| 48. |
Pick out the correct equation relating ' F ' and ' A '. |
| A. | F = A + PV |
| B. | F = E + A |
| C. | F = A - TS |
| D. | F = A + TS |
| Answer» B. F = E + A | |
| 49. |
The gas law ( PV = RT ) is true for an __________ change. |
| A. | isothermal |
| B. | adiabatic |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 50. |
In case of the decomposition of hydroiodic acid (2HI H 2 + I 2 ), addition of H 2 (at equilibrium condition) will |
| A. | increase the partial pressure of I 2 . |
| B. | decrease the partial pressure of HI. |
| C. | diminish the degree of dissociation of HI. |
| D. | none of these. |
| Answer» D. none of these. | |