MCQOPTIONS
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MCQOPTIONS
This section includes 409 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. |
Which one is the rate controlling step in a solid-gas non-catalytic reaction occurring at very high temperature ? |
| A. | Pore diffusion |
| B. | Film diffusion |
| C. | Ash layer diffusion |
| D. | Chemical reaction |
| Answer» C. Ash layer diffusion | |
| 2. |
With an increase in pressure in gaseous phase chemical reactions, the fractional conversion ______________ when the number of moles decreases? |
| A. | Increases |
| B. | Decreases |
| C. | Remain unaffected |
| D. | Unpredictable from the data |
| Answer» B. Decreases | |
| 3. |
With decrease in temperature, the equilibrium conversion of a reversible endothermic reaction_________________? |
| A. | Decreases |
| B. | Increases |
| C. | Remain unaffected |
| D. | Increases linearly with temperature |
| Answer» B. Increases | |
| 4. |
With increase in initial concentration, the fractional conversion of a first order reaction in a given time___________________? |
| A. | Increases |
| B. | Decreases |
| C. | Remain constant |
| D. | Unpredictable |
| Answer» D. Unpredictable | |
| 5. |
With increase in K2/K1 in case of a unimolecular type elementary reactions as shown in the bellow figure, the fractional yield of ‘R’ in mixed reactor (for a given conversion of ‘A’) ? |
| A. | Decreases |
| B. | Increases |
| C. | Increases linearly |
| D. | Remain same |
| Answer» B. Increases | |
| 6. |
With increase in temperature, the equilibrium _______________ rises in case of endothermic reaction? |
| A. | Constant |
| B. | Conversion |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» C. Both A. & B. | |
| 7. |
With increase in temperature, the rate constant obeying Arrhenius equation____________________? |
| A. | Increases |
| B. | Decreases |
| C. | Decreases exponentially |
| D. | Can either increase or decrease; depends on the frequency factor |
| Answer» D. Can either increase or decrease; depends on the frequency factor | |
| 8. |
With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion)? |
| A. | Increases |
| B. | Decreases |
| C. | Remain same |
| D. | Increases linearly |
| Answer» B. Decreases | |
| 9. |
With increase in the space time of an irreversible isothermal reaction being carried out in a P.F. reactor, the conversion will________________? |
| A. | Increase |
| B. | Decrease |
| C. | Remain same |
| D. | Data in insufficient; can’t be predicted |
| Answer» B. Decrease | |
| 10. |
With the same reaction time, initial concentration and feed rate, the reaction 2A → B is carried out separately in CSTR and P.F. reactor of equal volumes. The conversion will be__________________? |
| A. | Higher in P.F. reactor |
| B. | Higher in CSTR |
| C. | Same in both the reactors |
| D. | Data insufficient; can’t be predicted |
| Answer» B. Higher in CSTR | |
| 11. |
Which of the following is not a theory of homogeneous reaction ? |
| A. | Collision theory and activated complex theory |
| B. | Chain reaction theory |
| C. | Radiation hypothesis |
| D. | None of these |
| Answer» E. | |
| 12. |
Which of the following is not a dimension-less group used in catalysis? (Where, D = dispersion co-efficient, cm2/sec.D1 = diffusion co-efficient; cm2/sec L = length of the reactor, cm t = time, sec, v = volumetric flow rate, cm3/sec. V = volume, cm3.) ? |
| A. | Reactor dispersion number (D/vL) |
| B. | Reduced time (vt/V) |
| C. | Thiele modulus L √(k/D1) |
| D. | None of these |
| Answer» E. | |
| 13. |
Which of the following holds good for an elementary reaction as shown in the bellow figure ? |
| A. | The rate of disappearance of ‘Y’ is equal to the rate of appearance of ‘Z’ |
| B. | The rate of disappearance of ‘Y’ is equal to the rate of disappearance of ‘X’ |
| C. | Three times the rate of disappearance of ‘X’ is equal to the rate of appearance of ‘Z’ |
| D. | The rate of disappearance of ‘X’ is equal to the rate of appearance of ‘Z’ |
| Answer» D. The rate of disappearance of ‘X’ is equal to the rate of appearance of ‘Z’ | |
| 14. |
When the reaction occurs in the diffusion controlled region, the apparent activation energy as measured is only _______________ the true value? |
| A. | Twice |
| B. | Half |
| C. | Equal |
| D. | None of these |
| Answer» C. Equal | |
| 15. |
When the reaction is dominated by intraparticle diffusion, the apparent order of reaction (nD) as measured is related to the true order (n) as ________________? |
| A. | nD = (n + 1)/2 |
| B. | nD = n/2 |
| C. | nD = n + 1 |
| D. | None of these |
| Answer» B. nD = n/2 | |
| 16. |
When the density of the reaction mixture is constant in a chemical reaction, the ratio of the mean residence time to space time is__________________? |
| A. | > 1 |
| B. | < 1 |
| C. | 1 |
| D. | 0 |
| Answer» D. 0 | |
| 17. |
When an exothermic reversible reaction is conducted adiabatically, the rate of reaction____________________? |
| A. | Continuously increases |
| B. | Continuously decreases |
| C. | Passes through a maximum |
| D. | Passes through a minimum |
| Answer» D. Passes through a minimum | |
| 18. |
When all the limiting reactant is consumed in the reaction, the operational yield _______________ the relative yield? |
| A. | Is greater than |
| B. | Is smaller than |
| C. | Equals |
| D. | Can be either greater or smaller than (depends on the type of reaction) |
| Answer» D. Can be either greater or smaller than (depends on the type of reaction) | |
| 19. |
When a high liquid hold up is required in a reactor for gas liquid reaction, use ______________ column? |
| A. | Packed |
| B. | Spray |
| C. | Tray |
| D. | Bubble |
| Answer» E. | |
| 20. |
When a catalyst increases the rate of forward reaction, the value of rate constant__________________? |
| A. | Increases |
| B. | Decreases |
| C. | Remain same |
| D. | Becomes infinite |
| Answer» B. Decreases | |
| 21. |
When a catalyst increases the rate of chemical reaction, the rate constant_____________________? |
| A. | Decreases |
| B. | Increases |
| C. | Remain constant |
| D. | Become infinite |
| Answer» C. Remain constant | |
| 22. |
What is the value of ‘n’ if the reaction rate of the chemical reaction A → B, is proportional to CA n and it is found that the reaction rate triples, when the concentration of ‘A’ is increased 9 times ? |
| A. | 1/2 |
| B. | 1/3 |
| C. | 1/9 |
| D. | 3 |
| Answer» B. 1/3 | |
| 23. |
What is the order of chemical reaction as shown in the bellow figure, if it is found that the reaction rate doubles on doubling the concentration of B and also the reaction rate doubles when the concentrations of both A & B were doubled and quadrupled when the concentrations of both B & C were doubled ? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 24. |
What is the order of a chemical reaction of the bellow figure, if the rate of formation of ‘C’, increases by a factor of 2.82 on doubling the concentration of ‘A’ and increases by a factor of 9 on trebling the concentration of ‘B’ ? |
| A. | 7/2 |
| B. | 7/4 |
| C. | 5/2 |
| D. | 5/4 |
| Answer» B. 7/4 | |
| 25. |
What is the maximum possible value of FR(mole/sec.) ? |
| A. | 1/3 |
| B. | 1/2 |
| C. | 2/3 |
| D. | 2 |
| Answer» D. 2 | |
| 26. |
What is the dispersion number for a CSTR ? |
| A. | 0 |
| B. | 1 |
| C. | < 1 |
| D. | ∞ |
| Answer» E. | |
| 27. |
Volume change for unimolecular type first order reaction as shown in the bellow figure, increases _____________ with time? |
| A. | Linearly |
| B. | Exponentially |
| C. | Parabolically |
| D. | Logarithmically |
| Answer» C. Parabolically | |
| 28. |
Velocity of a chemical reaction___________________? |
| A. | Decreases with increase in temperature |
| B. | Increases with increase of pressure of reactants for all reactions |
| C. | Decreases with increase of reactant concentration |
| D. | None of these |
| Answer» E. | |
| 29. |
Velocity of a reaction depends upon the_________________? |
| A. | Nature of the reactants |
| B. | Concentration of the reactants |
| C. | Temperature at which the reaction is carried |
| D. | All A., B. and C. |
| Answer» E. | |
| 30. |
Vegetable oils are hydrogenated in a _______________ reactor? |
| A. | Slurry |
| B. | Plug flow |
| C. | Homogeneous catalytic |
| D. | None of these |
| Answer» B. Plug flow | |
| 31. |
Variables affecting the rate of homogeneous reactions are___________________? |
| A. | Pressure and temperature only |
| B. | Temperature and composition only |
| C. | Pressure and composition only |
| D. | Pressure, temperature and composition |
| Answer» E. | |
| 32. |
‘Unreacted core model’ represents the reaction involving ______________________? |
| A. | Combustion of coal particles |
| B. | Roasting of sulphide |
| C. | Manufacture of carbon disulphide from elements |
| D. | None of these |
| Answer» C. Manufacture of carbon disulphide from elements | |
| 33. |
Transition state theory relates the above quantities as___________________? |
| A. | k ∝ e-E/RT |
| B. | k ∝ T.eE/RT |
| C. | k ∝ √T |
| D. | k ∝ T1.5 |
| Answer» C. k ∝ √T | |
| 34. |
Transition state theory gives the rate constant as__________________? |
| A. | K α e-E/RT |
| B. | K α eE/RT |
| C. | K α T . e-E/RT |
| D. | K α √T . e-E/RT |
| Answer» D. K α √T . e-E/RT | |
| 35. |
Time required for 50% decomposition of a liquid in an isothermal batch reactor following first order kinetics is 2 minutes. The time required for 75% decomposition will be about _______________ minutes? |
| A. | 3 |
| B. | 4 |
| C. | 6 |
| D. | 10 |
| Answer» C. 6 | |
| 36. |
Threshold energy in a reaction is equal to the_________________? |
| A. | Activation energy |
| B. | Normal energy of reactants |
| C. | Sum of A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 37. |
Three plug flow reactors (PFR’s) of 4, 5 & 6 m3 volumes are arranged in two branches as shown below in the figure. If the total feed rate is 300 tons/hr, then for the same conversion in each branch, the feed rate through branch II should be ______________ tons/hr ? |
| A. | 100 |
| B. | 150 |
| C. | 200 |
| D. | 225 |
| Answer» B. 150 | |
| 38. |
Thermodynamic equilibrium constant in a system is affected by___________________? |
| A. | Inerts |
| B. | Pressure |
| C. | Temperature |
| D. | All A., B. & C. |
| Answer» D. All A., B. & C. | |
| 39. |
There is no correspondence between stoichiometric and the rate equation in case of a/an _____________ reaction? |
| A. | Elementary |
| B. | Multiple |
| C. | Autocatalytic |
| D. | Non-elementary |
| Answer» E. | |
| 40. |
The vessel dispersion number (D/μL) for plug flow is_________________? |
| A. | 0 |
| B. | 500 |
| C. | 750 |
| D. | ∞ |
| Answer» B. 500 | |
| 41. |
The value of Steric factor ‘P’ in the equation k = PZeE/RT usually ranges from ______________________? |
| A. | 1.0 to 10-8 |
| B. | 1.1 to 102 |
| C. | 0.1 to 0.9 |
| D. | None of these |
| Answer» B. 1.1 to 102 | |
| 42. |
The value of ‘n’ for a chemical reaction A → B, whose reaction rate is → CA n, will be _______________ if the rate of the reaction increases by a factor of 8, when the concentration of is doubled? |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» E. | |
| 43. |
The use of space time is preferred over the mean residence time in the design of a/an____________________? |
| A. | Batch reactor |
| B. | Ideal tubular-flow reactor |
| C. | Slurry reactor |
| D. | CSTR |
| Answer» C. Slurry reactor | |
| 44. |
The units of frequency factor in Arrhenius equation_________________? |
| A. | Are the same as those of the rate constant |
| B. | Depend on the order of the reaction |
| C. | Depend on temperature, pressure etc. of the reaction |
| D. | Are cycles per unit time |
| Answer» B. Depend on the order of the reaction | |
| 45. |
The unit of frequency factor in Arrhenius equation is_______________? |
| A. | Same as that of rate constant |
| B. | Same as that of activation energy |
| C. | Dimensionless |
| D. | None of these |
| Answer» B. Same as that of activation energy | |
| 46. |
The temperature dependence of reaction rate constant (K) by Arrhenius law is given by_______________? |
| A. | K α e-E/RT |
| B. | K α eE/RT |
| C. | K α T . e-E/RT |
| D. | K α √T . e-E/RT |
| Answer» B. K α eE/RT | |
| 47. |
The synthesis of proteins and metabolism in biological objects occur in the presence of biocatalyst called_________________? |
| A. | A ferment or an enzyme |
| B. | Haemoglobin |
| C. | Fungi |
| D. | None of these |
| Answer» D. None of these | |
| 48. |
The space time is equivalent to the holding time in a steady state mixed reactor for_____________________? |
| A. | Non-isothermal gas reaction |
| B. | Variable fluid density systems |
| C. | Constant fluid density systems |
| D. | Gas reactions with changing number of moles |
| Answer» D. Gas reactions with changing number of moles | |
| 49. |
The size of plug flow reactor (PFR) for all positive reaction orders and for any given duty, is _____________________ that of mixed reactor? |
| A. | Greater than |
| B. | Equal to |
| C. | Smaller than |
| D. | Unpredictable from the data |
| Answer» D. Unpredictable from the data | |
| 50. |
The single parameter model proposed for describing non-ideal flow is the ____________ model? |
| A. | Tank in series |
| B. | Dispersion |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |