MCQOPTIONS
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MCQOPTIONS
This section includes 590 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
The relation, Sc = Pr = 1, is valid, when the mechanism of ______________ transfer is same? |
| A. | Heat and mass |
| B. | Mass and momentum |
| C. | Heat and momentum |
| D. | Heat, momentum and mass |
| Answer» B. Mass and momentum | |
| 102. |
The relation among various mass transfer co-efficients (M.T.C) for ideal gases is given by (where, Kc & Km are M.T.C. for equimolar counter diffusion with concentration & mole fraction respectively as the driving force. and, Kp= M.T.C. for diffusion of a gas through a stagnant inert gas with pressure as driving force) ? |
| A. | Kc = Kp = Km |
| B. | Kc = Kp/RT = Km . RT/P |
| C. | Kc = Kp . RT = Km . RT/p |
| D. | None of these |
| Answer» D. None of these | |
| 103. |
The reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. The reflux ratio is____________________? |
| A. | 2 |
| B. | 0.5 |
| C. | 50 |
| D. | 150 |
| Answer» B. 0.5 | |
| 104. |
The recovery of penicillin from the acidified fermentation broth is done by__________________? |
| A. | Distillation |
| B. | Evaporation |
| C. | Absorption |
| D. | Liquid extraction |
| Answer» E. | |
| 105. |
The reciprocal of stripping factor is termed as ________________________? |
| A. | Selectivity index |
| B. | Relative volatility |
| C. | Absorption factor |
| D. | Murphree efficiency |
| Answer» D. Murphree efficiency | |
| 106. |
The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives___________________? |
| A. | Low pressure drop and high hold up |
| B. | High pressure drop and low hold up |
| C. | Low pressure drop and low hold up |
| D. | High pressure drop and high hold up |
| Answer» D. High pressure drop and high hold up | |
| 107. |
The ratio of Murphree plate efficiency to point efficiency is 1 in a ______________________ flow model? |
| A. | Plug |
| B. | Perfectly mixed |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» C. Both A. & B. | |
| 108. |
The ratio of Murphree plate efficiency to point efficiency is always > 1 in a _______________ flow model? |
| A. | Plug |
| B. | Perfectly mixed |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» B. Perfectly mixed | |
| 109. |
The rate of solid-liquid extraction is limited by the_________________? |
| A. | Phase change of the solute as it dissolves in the solvent |
| B. | Diffusion of the solute through the solvent in the pores to the outside of the particle |
| C. | Diffusion of the solute from the solution in contact with the particle to the main bulk of the solution |
| D. | All A , B. & C. |
| Answer» E. | |
| 110. |
The rate of mass transfer is not dependent upon the______________________? |
| A. | Degree of dispersion of one fluid in the other |
| B. | Interfacial surface exposed between the phases |
| C. | Both A. & B. |
| D. | None of these |
| Answer» E. | |
| 111. |
The process employing desorption of the absorbed solute by a solvent is called____________________? |
| A. | Elution |
| B. | Osmosis |
| C. | Reverse osmosis |
| D. | Sublimation |
| Answer» B. Osmosis | |
| 112. |
The percentage humidity is less than the relative humidity only at __________________ percent humidity? |
| A. | Zero |
| B. | Hundred |
| C. | Both zero and hundred |
| D. | None of these |
| Answer» D. None of these | |
| 113. |
The partial pressure distribution of an ideal gas diffusing through another stagnant ideal gas at steady state follows a/an _________________ law? |
| A. | Exponential |
| B. | Parabolic |
| C. | Linear |
| D. | Cubic |
| Answer» B. Parabolic | |
| 114. |
The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by___________________? |
| A. | Increasing the gas film co-efficient |
| B. | Increasing the liquid film co-efficient |
| C. | Increasing the total pressure |
| D. | Decreasing the total pressure |
| Answer» B. Increasing the liquid film co-efficient | |
| 115. |
The operation involved when the soluble material is largely on the surface of an insoluble solid and is merely washed off by the solvent is called__________________? |
| A. | Decoction |
| B. | Percolation |
| C. | Elutriation or elution |
| D. | None of these |
| Answer» D. None of these | |
| 116. |
The operating line for an absorber is curved, when plotted in terms of _______________________? |
| A. | Mole fractions |
| B. | Mole ratios |
| C. | Partial pressure |
| D. | Mass fractions |
| Answer» D. Mass fractions | |
| 117. |
The operating cost of a distillation column at minimum reflux ratio is____________________? |
| A. | Minimum |
| B. | Maximum |
| C. | Infinite |
| D. | Zero |
| Answer» B. Maximum | |
| 118. |
The most efficient cooling tower out of the following is_____________________? |
| A. | Induced draft |
| B. | Forced draft |
| C. | Natural draft |
| D. | Atmospheric |
| Answer» B. Forced draft | |
| 119. |
The most economical range of absorption factor is____________________? |
| A. | 0 to 0.5 |
| B. | 0 to 3 |
| C. | 1.25 to 2 |
| D. | 5 to 15 |
| Answer» D. 5 to 15 | |
| 120. |
The most common packing used in industrial operations is _______________ rings? |
| A. | Raschig |
| B. | Lessing |
| C. | Cross-partition |
| D. | Single spiral |
| Answer» B. Lessing | |
| 121. |
The minimum number of theoretical plates is required for achieving a given separation in distillation column with_________________? |
| A. | No reflux |
| B. | Total reflux |
| C. | Zero reflux ratio |
| D. | Minimum reflux ratio |
| Answer» C. Zero reflux ratio | |
| 122. |
The minimum liquid rate to be used in an absorber corresponds to an operating line_______________________? |
| A. | Of slope = 1 |
| B. | Of slope = 0.1 |
| C. | Tangential to the equilibrium curve |
| D. | None of these |
| Answer» D. None of these | |
| 123. |
The minimum liquid rate to be used in an absorber corresponds to an operating line__________________? |
| A. | Of slope = 1 |
| B. | Of slope = 0.1 |
| C. | Tangential to the equilibrium curve |
| D. | None of these |
| Answer» D. None of these | |
| 124. |
The McCabe ΔL law states that the____________________? |
| A. | Molar heats of vaporisation of components are nearly equal |
| B. | Linear crystal growth rate depends on the degree of super-saturation |
| C. | Linear crystal growth rate does not depend on the crystal size |
| D. | Linear crystal growth rate depends on the crystal size |
| Answer» D. Linear crystal growth rate depends on the crystal size | |
| 125. |
The mass transfer co-efficient for a solid sphere of radius ‘a’ dissolving in a large volume of quiescent liquid, in which „D’ is the diffusivity of solute, is _____________________? |
| A. | D/a |
| B. | D/2a |
| C. | Proportional to √D |
| D. | Dependent on the Reynolds number |
| Answer» E. | |
| 126. |
The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = _________________? |
| A. | 1 |
| B. | 0.5 |
| C. | 10 |
| D. | 0 |
| Answer» B. 0.5 | |
| 127. |
The main reason for dividing a tall packed tower into series of small towers is to________________________? |
| A. | Minimise the overall pressure drop |
| B. | Avoid flooding |
| C. | Reduce liquid hold up |
| D. | Avoid channelling |
| Answer» E. | |
| 128. |
The Knudsen diffusivity is proportional to (where, T = absolute temperature) ______________________? |
| A. | √T |
| B. | T2 |
| C. | T |
| D. | T4 |
| Answer» B. T2 | |
| 129. |
The Knudsen diffusivity is dependent on the ______________________? |
| A. | Molecular velocity only |
| B. | Pore radius of the catalyst only |
| C. | Molecular mean free path only |
| D. | Molecular velocity and pore radius of the catalyst |
| Answer» E. | |
| 130. |
The interfacial area per unit volume of dispersion, in a gas-liquid contactor, for fractional hold up of gas = 0.1 and gas bubble diameter = 0.5 mm is given by (in m2/m3) ? |
| A. | 500 |
| B. | 1200 |
| C. | 900 |
| D. | 800 |
| Answer» B. 1200 | |
| 131. |
The interfacial area per unit volume of dispersion, in a gas-liquid contactor, for fractional hold up of gas = 0.1 and gas bubble diameter = 0.5 mm is given by (in m2/m3)_________________? |
| A. | 500 |
| B. | 1200 |
| C. | 900 |
| D. | 800 |
| Answer» B. 1200 | |
| 132. |
The individual mass transfer co-efficients (moles/m2s) for absorption of a solute from a gas mixture into a liquid solvent are, KL = 4.5 and KG = 1.5. The slope of the equilibrium line is 3. Which of the following resistance (s) is (are) controlling ? |
| A. | Liquid side |
| B. | Gas side |
| C. | Interfacial |
| D. | Both liquid and gas side |
| Answer» C. Interfacial | |
| 133. |
The humid volume may be increased by increasing the____________________? |
| A. | Temperature at constant humidity |
| B. | Humidity at constant temperature |
| C. | Both A. and B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 134. |
The Hatta number is important in______________________? |
| A. | Multi-component distillation |
| B. | Binary distillation |
| C. | Gas absorption without chemical reaction |
| D. | Gas absorption with chemical reaction |
| Answer» E. | |
| 135. |
The Hatta number is important in_________________? |
| A. | Multi-component distillation |
| B. | Binary distillation |
| C. | Gas absorption without chemical reaction |
| D. | Gas absorption with chemical reaction |
| Answer» E. | |
| 136. |
The following plot gives the saturated humidity (He) versus temperature (T).Line joining (H1, T1) and (H2, T2) is the constant enthalpy line. Choose the correct one from among the alternatives A, B, C and D____________________? |
| A. | T1-Dew point temp; T2-Dry bulb temp; T3-Wet bulb temp |
| B. | T1-Dew point temp; T2-Wet bulb temp; T3-Dry bulb temp |
| C. | T1-Wet bulb temp; T2-Dry bulb temp; T3-Dew point temp |
| D. | T1-Dry bulb temp; T2-Wet bulb temp; T3-Dew point temp |
| Answer» E. | |
| 137. |
The film penetration model of mass transfer was enunciated by______________________? |
| A. | Gilliland |
| B. | Toor and Marcello |
| C. | Stefan |
| D. | Fick |
| Answer» C. Stefan | |
| 138. |
The feed to fractionating column is changed from saturated vapour to saturated liquid. If the separation and reflux ratio remains unchanged, the number of ideal stages will______________________? |
| A. | Increase |
| B. | Decrease |
| C. | Remain same |
| D. | Depend on saturated boiling point; may increase or decrease |
| Answer» B. Decrease | |
| 139. |
The falling rate period in the drying of a solid is characterised by__________________? |
| A. | Increase in rate of drying |
| B. | Increasing temperatures both on the surface and within the solid |
| C. | Decreasing temperatures |
| D. | None of these |
| Answer» C. Decreasing temperatures | |
| 140. |
The expression, ln(F/W) = ∫xF xW [dx/y* – x)] is_____________________? |
| A. | Differential distillation equation |
| B. | For NtoG in absorption for dilute mixture |
| C. | Slope of q-line in McCabe-Thiele method |
| D. | For relative volatility |
| Answer» B. For NtoG in absorption for dilute mixture | |
| 141. |
The expression, y(1 – x)/x(1 – y) is for_____________________? |
| A. | Absorption factor |
| B. | Relative volatility |
| C. | Selectivity |
| D. | Murphree efficiency |
| Answer» C. Selectivity | |
| 142. |
The equipment used in the extraction of highly corrosive radioactive liquids is_______________________? |
| A. | Pulse column |
| B. | Spray column |
| C. | Mixer settler |
| D. | Baffle tower |
| Answer» B. Spray column | |
| 143. |
The equipment frequently used for adiabatic humidification-cooling operation with recirculating liquid is_________________? |
| A. | Natural draft cooling tower |
| B. | Induced draft cooling tower |
| C. | Spray chamber |
| D. | None of these |
| Answer» D. None of these | |
| 144. |
The equilibrium liquid composition compared to the vapor composition in case of________________?_x005F_x000D_Azeotropic mixture is |
| A. | More |
| B. | Less |
| C. | Same |
| D. | Either more or less; depends on the system |
| Answer» D. Either more or less; depends on the system | |
| 145. |
The equation, NA = (DAB . Pt /RTZ) (y1 – y2) is for _______________________? |
| A. | Steady state equimolar counter diffusion |
| B. | Fick’s first law of diffusion |
| C. | Steady state diffusion for stagnant case |
| D. | Liquid M.T.C. by penetration theory |
| Answer» B. Fick’s first law of diffusion | |
| 146. |
The equation, NA = (DAB . Pt /RTZ . PBM) (PA1 – PA2) is for_______________________? |
| A. | Fick’s second law of diffusion |
| B. | Steady state diffusion for stagnant case |
| C. | Liquid M.T.C. by Higbie penetration theory |
| D. | None of these |
| Answer» C. Liquid M.T.C. by Higbie penetration theory | |
| 147. |
The efficiency of a plate column will be maximum, when the flow is ideal __________________ the plate? |
| A. | Across |
| B. | Above |
| C. | Both A. & B. |
| D. | Neither A. nor B. |
| Answer» D. Neither A. nor B. | |
| 148. |
The drying time between fixed moisture contents within the ‘constant rate period’ is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid) ? |
| A. | √T |
| B. | T |
| C. | T1.5 |
| D. | T3 |
| Answer» C. T1.5 | |
| 149. |
The drying time between fixed moisture content within diffusion controlled ‘falling rate period’ is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid) ? |
| A. | √T |
| B. | T |
| C. | T2 |
| D. | T3 |
| Answer» D. T3 | |
| 150. |
The dimension of diffusivity is same as that of the__________________? |
| A. | Density |
| B. | Molal concentration |
| C. | Kinematic viscosity |
| D. | Velocity head |
| Answer» D. Velocity head | |