MCQOPTIONS
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MCQOPTIONS
This section includes 591 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
*/*_Molecular seives are porous? |
| A. | Alumina |
| B. | Silica |
| C. | Synthetic zeolites crystals/metal alumino-silicates |
| D. | None of these |
| Answer» D. None of these | |
| 152. |
*/*_1 kg of a saturated aqueous solution of a highly soluble component A at 60°C is cooled to 25°C. The solubility limits of A are (0.6 kgA/kg water) at 60°C and (0.2 kgA/kg water) at 25°C. The amount in kg of the crystals formed is? |
| A. | 0.4 |
| B. | 0.25 |
| C. | 0.2 |
| D. | 0.175 |
| Answer» D. 0.175 | |
| 153. |
*/*_Can the efficiency of a plate in the distillation tower be greater than 100%?? |
| A. | Yes |
| B. | Normally not; but is possible if infinite number of plates are put |
| C. | Never |
| D. | Yes ; if the reflux ratio is maximum |
| Answer» D. Yes ; if the reflux ratio is maximum | |
| 154. |
*/*_Water-ethyl alcohal solution can be concentrated (in respect of alcohal concentration) by __________ distillation.? |
| A. | Atmospheric |
| B. | Vacuum |
| C. | High pressure |
| D. | None of these |
| Answer» C. High pressure | |
| 155. |
*/*_Very tall packed towers are divided into series of beds to? |
| A. | Reduce the overall pressure drop |
| B. | Avoid channelling |
| C. | Reduce liquid hold-up |
| D. | Avoid flooding |
| Answer» C. Reduce liquid hold-up | |
| 156. |
*/*_In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at __________ reflux.? |
| A. | Total |
| B. | Minimum |
| C. | Operating |
| D. | Maximum permissible |
| Answer» B. Minimum | |
| 157. |
*/*_Sides of equilateral-triangular co-ordinates (on which ternary liquid system is plotted) represent? |
| A. | A pure component |
| B. | A binary mixture |
| C. | A ternary mixture |
| D. | Partially miscible ternary system |
| Answer» C. A ternary mixture | |
| 158. |
*/*_Molecular seives are regenerated by heating to __________ °C.? |
| A. | < 150 |
| B. | 200-330 |
| C. | > 500 |
| D. | > 1000 |
| Answer» C. > 500 | |
| 159. |
*/*_Diffusion in concentrated solutins differs from that in dilute solutions, because of the change in the __________ with the concentration of the solution.? |
| A. | Degree of ideality |
| B. | Viscosity |
| C. | Both A & B |
| D. | Neither A nor B |
| Answer» D. Neither A nor B | |
| 160. |
*/*_Bollman extractor? |
| A. | Is a static bed leaching equipment |
| B. | Is used for extraction of oil from oilseed |
| C. | Is a centrifugal extractor |
| D. | Employs only counter-current extraction |
| Answer» C. Is a centrifugal extractor | |
| 161. |
*/*_Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the? |
| A. | Packing may be crushed due to thermal expansion/contraction of the components of the equipments |
| B. | Pressure drop in the equipment will be very high |
| C. | Viscosity variation of the fluids may cause channeling/flooding |
| D. | None of these |
| Answer» B. Pressure drop in the equipment will be very high | |
| 162. |
*/*_Which of the following parameters remains almost constant during adiabatic saturation of unsaturated air?? |
| A. | Dry bulb temperature |
| B. | Dew point |
| C. | Wet bulb temperature |
| D. | None of these |
| Answer» D. None of these | |
| 163. |
*/*_In an operating distillation column, the? |
| A. | Vapors and liquids are at their dew point and bubble point respectively |
| B. | Driving force for the liquid flow is its specific weight |
| C. | Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column |
| D. | Highest temperature is encountered at the top of the column |
| Answer» D. Highest temperature is encountered at the top of the column | |
| 164. |
*/*_Penetration model (theory) for mass transfer was enunciated by? |
| A. | Danckwerts |
| B. | Toor and Marchello |
| C. | Higbie |
| D. | Kissinevskii |
| Answer» D. Kissinevskii | |
| 165. |
*/*_In distillation column design, the McCabe-Thiele procedure is inadequate and a Ponchan-Savarit procedure is needed, when? |
| A. | Saturated feed is not used |
| B. | An azeotrope forms |
| C. | The latent heat of vaporisation of the more and less volatile components are greatly different |
| D. | A total condenser is used |
| Answer» E. | |
| 166. |
*/*_Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid )? |
| A. | P = P |
| B. | P >>P |
| C. | P < P |
| D. | P << P |
| Answer» B. P >>P | |
| 167. |
*/*_Coffee is prepared from coffee beans by leaching with? |
| A. | Cold water |
| B. | Hot water |
| C. | Dilute hot caustic solution |
| D. | Naphtha |
| Answer» C. Dilute hot caustic solution | |
| 168. |
*/*_Which is not concerned directly with mass transfer?? |
| A. | Schmidt number |
| B. | Sherwood number |
| C. | Lewis relationship |
| D. | Froude number |
| Answer» E. | |
| 169. |
*/*_Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations.? |
| A. | Sherwood number in mass transfer is analogous to Nusselt number in heat transfer |
| B. | Prandtl number in heat transfer is analogous to Schmidt number in mass transfer |
| C. | Reynolds number in mass transfer is analogous to Grashoff number in heat transfer |
| D. | Reynolds number remains the same in both heat and mass transfer |
| Answer» D. Reynolds number remains the same in both heat and mass transfer | |
| 170. |
*/*_Leaching of coarse solid lumps is also termed as? |
| A. | Decoction |
| B. | Dissolution |
| C. | Percolation |
| D. | Agitation and settling |
| Answer» D. Agitation and settling | |
| 171. |
*/*_Dew point of a gas-vapour mixture? |
| A. | Increases with temperature rise |
| B. | Decreases with temperature rise |
| C. | Decreases with decrease in pressure |
| D. | Increases with increase in pressure |
| Answer» D. Increases with increase in pressure | |
| 172. |
*/*_A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids)? |
| A. | M(Xo - XF) |
| B. | M(Xo/XF) |
| C. | M ln(Xo/XF) |
| D. | MXo ln(Xo/XF) |
| Answer» E. | |
| 173. |
*/*_In case of an absorber, the operating? |
| A. | Line always lies above the equilibrium curve |
| B. | Line always lies below the equilibrium curve |
| C. | Line can be either above or below the equilibrium curve |
| D. | Velocity is more than the loading velocity |
| Answer» B. Line always lies below the equilibrium curve | |
| 174. |
*/*_In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of? |
| A. | Area between operating line and 45° diagonal x-y diagram |
| B. | Condenser and reboiler surfaces |
| C. | Tower cross-section |
| D. | None of these |
| Answer» B. Condenser and reboiler surfaces | |
| 175. |
*/*_Experimental determination of __________ is done by wetted wall column method.? |
| A. | Diffusion co-efficient |
| B. | Mass transfer co-efficient |
| C. | NTU |
| D. | None of these |
| Answer» C. NTU | |
| 176. |
*/*_Drying of a solid involves __________ transfer.? |
| A. | Only heat |
| B. | Only mass |
| C. | Both heat and mass |
| D. | None of these |
| Answer» D. None of these | |
| 177. |
*/*_If f = moles of vapour present per mole of feed, then the slope of feed line is (Mcabe-Thiele method)? |
| A. | (1 - f)/f |
| B. | - (f - 1)/f |
| C. | - 1/f |
| D. | - f/(1 - f) |
| Answer» D. - f/(1 - f) | |
| 178. |
*/*_Absorption factor, for a fixed degree of absorption from a fixed amount of gas should be? |
| A. | 1 |
| B. | > 1 |
| C. | < 1 |
| D. | ≤ 1 |
| Answer» C. < 1 | |
| 179. |
*/*_The diffusivity, DAB (for component A diffusing in B) is equal to the diffusivity Dsub>BA (for component B diffusing in A) for a binary mixture of? |
| A. | Newtonion liquids |
| B. | Non-Newtonion liquids |
| C. | Ideal gases |
| D. | Real gases |
| Answer» D. Real gases | |
| 180. |
*/*___________ is the separation technique used for desalination of sea water.? |
| A. | Thermal diffusion |
| B. | Reverse osmosis |
| C. | Adsorption |
| D. | Absorption |
| Answer» C. Adsorption | |
| 181. |
*/*_Experiments were conducted to determine the flux of a species A in a stagnant medium across a gas-liquid interface. The overall mass transfer co-efficient based on the liquid side for dilute systems for the above was estimated to be 4 x 10⁻³ kg mole/m².s. The equilibrium data for the system is given as y = 2x. The flux across the interface (in kg mole/m² .s) for bulk concentrations of A in gas phase and liquid phase as y = 0.4 and x = 0.01 respectively is? |
| A. | 5.6 x 10⁻⁴ |
| B. | 8.5 x 10⁻⁴ |
| C. | 5.6 x 10⁻³ |
| D. | 8.5 x 10⁻³ |
| Answer» C. 5.6 x 10‚Äö√Ö¬™¬¨‚â• | |
| 182. |
*/*_Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is __________ the liquid head available in the downcomer.? |
| A. | Less than |
| B. | More than |
| C. | Same as |
| D. | Very much less |
| Answer» C. Same as | |
| 183. |
*/*_Operating velocity in a packed tower is usually __________ the flooding velocity.? |
| A. | Half |
| B. | Twice |
| C. | Equal to |
| D. | More than |
| Answer» B. Twice | |
| 184. |
*/*_The relative volatility of a binary mixture at constant temperature __________ the total pressure.? |
| A. | Decreases with increase in |
| B. | Increases with increase in |
| C. | Is independent of |
| D. | None of these |
| Answer» B. Increases with increase in | |
| 185. |
*/*_Which of the following assumes constant molal vaporisation and overflow?? |
| A. | McCabe-Thiele method |
| B. | Ponchan-Savarit method |
| C. | Enthalpy concentration method |
| D. | Plate absorption column |
| Answer» B. Ponchan-Savarit method | |
| 186. |
*/*_With increase in temperature, the mutual solubility of two liquids? |
| A. | Increases |
| B. | Decreases |
| C. | Remains unchanged |
| D. | Decreases exponentially |
| Answer» B. Decreases | |
| 187. |
*/*_Pick out the correct relationship. (where, Ri = internal reflux ratio Ro = external reflux ratio. )? |
| A. | (1 + Ro) = Ro/Ri |
| B. | (1 - Ro) = Ro/Ri |
| C. | (1 + Ri) = Ro/Ri |
| D. | (1 - Ri) = Ro/Ri |
| Answer» B. (1 - Ro) = Ro/Ri | |
| 188. |
*/*_Which of the following decreases during evaporative cooling process with recirculated water supply?? |
| A. | Wet bulb temperature |
| B. | Relative humidity |
| C. | Partial pressure of vapour |
| D. | None of these |
| Answer» E. | |
| 189. |
*/*_In liquid extraction, if the selectivity is unity, then? |
| A. | Separation of the constituents is the most effective |
| B. | No separation will occur |
| C. | Amount of solvent required will be minimum |
| D. | Solvent flow rate should be very low |
| Answer» C. Amount of solvent required will be minimum | |
| 190. |
*/*_(NRe . NSc) is termed in mass transfer operation as the __________ number.? |
| A. | Stanton |
| B. | Sherwood |
| C. | Peclet |
| D. | None of these |
| Answer» D. None of these | |
| 191. |
*/*_Which of the following equipments is not used for liquid dispersion?? |
| A. | Wetted wall towers |
| B. | Packed towers |
| C. | Venturi scrubbers |
| D. | Agitated vessels |
| Answer» E. | |
| 192. |
*/*_Pick out the wrong statement pertaining to leaching.? |
| A. | Fine solids can not be leached in a Pachuka tank |
| B. | Door classifier can be used for leaching of coarse solids |
| C. | Vegetable seeds can be leached in either of Bollman extractor, Rotocel or Kennedy extractor |
| D. | Very high temperature is not needed for the leaching of sugar beet |
| Answer» B. Door classifier can be used for leaching of coarse solids | |
| 193. |
*/*_When both the fluids flow concurrently in an absorber, the slope of the operating line is? |
| A. | - ve |
| B. | + ve |
| C. | 1 |
| D. | -1 |
| Answer» B. + ve | |
| 194. |
*/*_For water-ethanol system, the minimum reflux ratio? |
| A. | Is computed from the slope of the upper operating line that is tangent to the equilibrium curve |
| B. | Is computed from the intercept of the operating line |
| C. | Cannot be computed |
| D. | Is the optimum reflux ratio |
| Answer» B. Is computed from the intercept of the operating line | |
| 195. |
*/*_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 | |
| 196. |
*/*_Solvent used in extractive distillation? |
| A. | Changes the relative volatility of the original components |
| B. | Should be of high volatility |
| C. | Should form azeotropes with the original components |
| D. | All of the above |
| Answer» B. Should be of high volatility | |
| 197. |
*/*_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. | |
| 198. |
*/*_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 por radius of the catalyst |
| Answer» E. | |
| 199. |
*/*_The cooling effect in a cooling tower can be speeded up by? |
| A. | Increasing the air velocity and area of exposed wet surface |
| B. | Reducing the barometric pressure |
| C. | Reducing the humidity of the air |
| D. | All of the above |
| Answer» E. | |
| 200. |
*/*_Stacked packing compared to dumped packing? |
| A. | Provides poorer contact between the fluids |
| B. | Gives lower pressure drop |
| C. | Both A & B |
| D. | Gives higher pressure drop |
| Answer» D. Gives higher pressure drop | |