MCQOPTIONS
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MCQOPTIONS
This section includes 1443 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1351. |
A catalyst promoter |
| A. | Improves the activity of a catalyst |
| B. | Acts as a catalyst support |
| C. | Itself has very high activity |
| D. | All (A), (B) and (C) |
| Answer» B. Acts as a catalyst support | |
| 1352. |
In a CSTR __________ varies with time. |
| A. | In a CSTR __________ varies with time. |
| B. | Concentration |
| C. | Both (A) & (B) |
| D. | Neither (A) nor (B) |
| Answer» E. | |
| 1353. |
The enzyme which can catalyse the conversion of glucose to ethyl alcohol is |
| A. | Invertase |
| B. | Maltase |
| C. | Diastase |
| D. | Zymase |
| Answer» E. | |
| 1354. |
The rate constant of a reaction depends on the |
| A. | Initial concentration of reactants |
| B. | Time of reaction |
| C. | Temperature of the system |
| D. | Extent of reaction |
| Answer» D. Extent of reaction | |
| 1355. |
The time needed to achieve the same fractional conversion for particles of different sizes (D) when chemical reaction controls, is proportional to |
| A. | d |
| B. | √d |
| C. | d 1.5 |
| D. | d 2 |
| Answer» B. √d | |
| 1356. |
The reaction A → B is conducted in an isothermal batch reactor. If the conversion of A increases linearly with holding time, then the order of the reaction is |
| A. | 0 |
| B. | 1 |
| C. | 1.5 |
| D. | 2 |
| Answer» B. 1 | |
| 1357. |
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 | |
| 1358. |
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 | |
| 1359. |
The equilibrium constant ‘K’ of a chemical reaction depends on |
| A. | Temperature only |
| B. | Pressure only |
| C. | Temperature and pressure |
| D. | Ratio of reactants |
| Answer» B. Pressure only | |
| 1360. |
For a zero order reaction, the concentration of product increases with the |
| A. | Increase of reaction time |
| B. | Increase in initial concentration |
| C. | Total pressure |
| D. | Decrease in total pressure |
| Answer» B. Increase in initial concentration | |
| 1361. |
The preferred reacting system for oxidation of o-xylene to phthalic anhydride is |
| A. | Jacketed liquid phase CSTR |
| B. | Jacketed steam heated multitubular reactor |
| C. | Multitubular reactor with cooling |
| D. | Multistage multitubular reactor with interstage cooling |
| Answer» B. Jacketed steam heated multitubular reactor | |
| 1362. |
The gas phase reaction 2A ⇌ B is carried out in an isothermal plug flow reactor. The feed consists of 80 mole % A and 20 mole % inerts. If the conversion of A at the reactor exit is 50%, then CA/CA0 at the outlet of the reactor is |
| A. | 2/3 |
| B. | 5/8 |
| C. | 1/3 |
| D. | 3/8 |
| Answer» C. 1/3 | |
| 1363. |
The exit age distribution of fluid leaving a vessel is used to know the |
| A. | Activation energies of a reaction |
| B. | Reaction mechanism |
| C. | Extent of non-ideal flow in the vessel |
| D. | None of these |
| Answer» D. None of these | |
| 1364. |
Which of the following is the optimum operating condition for an exothermic reversible reaction taking place in a plug-flow reactor? |
| A. | Temperature should be high in the beginning and decreased towards the end of the reaction |
| B. | Very low temperature should be used throughout the reaction |
| C. | Very high temperature should be used throughout the reaction |
| D. | None of these |
| Answer» B. Very low temperature should be used throughout the reaction | |
| 1365. |
Non-catalytic fluid-solid reactions are represented by __________ model. |
| A. | Continuous reaction |
| B. | Unreacted core |
| C. | Both (A) and (B) |
| D. | Neither (A) and (B) |
| Answer» D. Neither (A) and (B) | |
| 1366. |
What is the order of a chemical reaction whose rate is deter-mined by the variation of one concentration term only? |
| A. | Zero |
| B. | First |
| C. | Second |
| D. | Third |
| Answer» C. Second | |
| 1367. |
In which of the following gaseous phase reactions, the equilibrium of the reaction remains unaffected by pressure changes? |
| A. | 2O3 ⇌ 3O2 |
| B. | N2 + O2 ⇌ 2NO |
| C. | 2NO2 ⇌ N2O4 |
| D. | 2SO2 + O2 ⇌ 2SO3 |
| Answer» C. 2NO2 ⇌ N2O4 | |
| 1368. |
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 | |
| 1369. |
For all positive reaction orders for a particular duty, |
| A. | Mixed reactor is always larger than the plug-flow reactor |
| B. | Ratio of the volume of the mixed reactor to that of the plug-flow reactor decreases with order |
| C. | Reactor size is independent of the type of flow |
| D. | Density variation during reaction affects design |
| Answer» B. Ratio of the volume of the mixed reactor to that of the plug-flow reactor decreases with order | |
| 1370. |
A reaction which is catalysed by a base is catalysed by all substances which have a tendency to |
| A. | Lose a proton |
| B. | Gain a proton |
| C. | Gain an electron |
| D. | None of these |
| Answer» C. Gain an electron | |
| 1371. |
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 | |
| 1372. |
If ΔG (free energy change) for a chemical reaction is very large and negative, then the reaction is |
| A. | Not feasible |
| B. | Just feasible |
| C. | Very much feasible |
| D. | Unpredictable as ΔG is no measure of feasibility of a reaction |
| Answer» D. Unpredictable as ΔG is no measure of feasibility of a reaction | |
| 1373. |
_________ catalytic reaction is involved in the thermal cracking of gas oil. |
| A. | Homogeneous |
| B. | Non-Homogeneous |
| C. | Heterogeneous |
| D. | Non-Heterogeneous |
| Answer» B. Non-Homogeneous | |
| 1374. |
Limiting reactant in a chemical reaction decides the |
| A. | Rate constant |
| B. | Conversion |
| C. | Reaction speed |
| D. | Equilibrium constant |
| Answer» C. Reaction speed | |
| 1375. |
The residence time distribution of an ideal CSTR is |
| A. | (1/η) exp (-t/η) |
| B. | η exp (-t/η) |
| C. | exp (-t/η) |
| D. | (1/η) (-t/η) |
| Answer» D. (1/η) (-t/η) | |
| 1376. |
Which of the following fixes the volume of a batch reactor for a particular conversion and production rate? |
| A. | Operating conditions (e.g. pressure and temperature) |
| B. | Rate constant |
| C. | Density of mixture |
| D. | None of these |
| Answer» D. None of these | |
| 1377. |
Which of the following is not a unit of reaction rate? |
| A. | Moles for med/(surface of catalyst) (time) |
| B. | Moles formed/volume of reactor) (time) |
| C. | Mole formed/volume of catalyst) (time) |
| D. | None of these |
| Answer» E. | |
| 1378. |
A batch reactor suffers from following disadvantage. |
| A. | Poor product quality control |
| B. | High labour and handling cost |
| C. | High shutdown time requirement for emptying, cleaning and refilling |
| D. | All (A), (B) and (C) |
| Answer» E. | |
| 1379. |
A catalyst in a chemical reaction |
| A. | Decreases the activation energy |
| B. | Alters the reaction mechanism |
| C. | Increases the frequency of collisions of reacting species |
| D. | All (A), (B) and (C) |
| Answer» E. | |
| 1380. |
A catalyst inhibitor |
| A. | Lessens its selectivity |
| B. | May be useful for suppressing undesirable side reactions |
| C. | Is added in small quantity during the catalyst manufacture itself |
| D. | All (A), (B) and (C) |
| Answer» E. | |
| 1381. |
Calcination reaction of limestone (CaCO3 → CaO + CO2) goes to completion in the rotary kiln, because |
| A. | CaO is not dissociated |
| B. | CO2 escapes continuously |
| C. | Of high calcination temperature |
| D. | CaO is more stable than CaCO3 |
| Answer» C. Of high calcination temperature | |
| 1382. |
Mean residence time is equal to the space time, when |
| A. | The feed rate is measured at temperature and pressure in the reactor |
| B. | The temperature, pressure and the density of reaction mixture remains constant throughout the reactor |
| C. | There is no change in number of moles in gaseous reaction |
| D. | All (A), (B) and (C) |
| Answer» E. | |
| 1383. |
Which of the following curves shows the effect of temperature on the extent of gas-solid adsorption at a given pressure? |
| A. | Langmuir adsorption isotherm |
| B. | Adsorption isobar |
| C. | Freundlich adsorption isotherm |
| D. | None of these |
| Answer» C. Freundlich adsorption isotherm | |
| 1384. |
Promoter is added to the catalyst to improve its |
| A. | Porosity |
| B. | Sensitivity |
| C. | Surface area |
| D. | None of these |
| Answer» C. Surface area | |
| 1385. |
Knudsen diffusion is directly proportional to |
| A. | T |
| B. | √T |
| C. | 1/√T |
| D. | T 2 |
| Answer» C. 1/√T | |
| 1386. |
A batch reactor is characterised by |
| A. | Constant residence time |
| B. | Variation in extent of reaction and properties of the reaction mixture with time |
| C. | Variation in reactor volume |
| D. | Very low conversion |
| Answer» C. Variation in reactor volume | |
| 1387. |
Exposure of a photographic plate to produce a latent image is an example of __________ reaction. |
| A. | Very slow |
| B. | Very fast |
| C. | Photochemical |
| D. | Both (B) and (C |
| Answer» E. | |
| 1388. |
Concentration of the limiting reactant (with initial concentration of a moles/litre) after time t is (a-x). Then 't' for a first order reaction is given by |
| A. | k. t = ln a/(a - x) |
| B. | k. t = x/a (a - x) |
| C. | k. t = ln (a - x)/a |
| D. | k. t = ln a (a - x)/x |
| Answer» B. k. t = x/a (a - x) | |
| 1389. |
In case of calcination of limestone, CaCO3 CaO + CO2, the addition of more of CaO will result in __________ in the concentration of CO2. |
| A. | No change |
| B. | Increase |
| C. | Decrease |
| D. | Unpredictable from the data |
| Answer» B. Increase | |
| 1390. |
The rate of the chemical reaction A → B doubles as the concentration of A i.e.., CA is doubled. If rate of reaction is proportional to CA n , then what is the value of n for this reaction? |
| A. | 0 |
| B. | 0.5 |
| C. | 1 |
| D. | 2 |
| Answer» D. 2 | |
| 1391. |
A second order reaction of the form A + B → C is called a pseudo-first order reaction, when |
| A. | CA0 = CB0 |
| B. | CA0 > CB0 |
| C. | CB0 > CA0 |
| D. | CB0 ≥ CB0 |
| Answer» E. | |
| 1392. |
Arrhenius equation shows the variation of __________ with temperature. |
| A. | Reaction rate |
| B. | Rate constant |
| C. | Energy of activation |
| D. | Frequency factor |
| Answer» C. Energy of activation | |
| 1393. |
Pure A in gas phase enters a reactor 50% of this A is converted to B through the reaction, A → 3B. Mole fraction of A in the exit stream is |
| A. | 1/2 |
| B. | 1/3 |
| C. | 1/4 |
| D. | 1/5 |
| Answer» C. 1/4 | |
| 1394. |
The rate constant of a chemical reaction increases by increasing the |
| A. | Temperature |
| B. | Pressure |
| C. | Reactants concentration |
| D. | None of these |
| Answer» B. Pressure | |
| 1395. |
A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction. |
| A. | Less than |
| B. | Equal to |
| C. | More than |
| D. | Equal to or more than |
| Answer» E. | |
| 1396. |
Catalyst is a substance, which __________ chemical reaction. |
| A. | Increases the speed of a |
| B. | Decreases the speed of a |
| C. | Can either increase or decrease the speed of a |
| D. | Alters the value of equilibrium constant in a reversible |
| Answer» D. Alters the value of equilibrium constant in a reversible | |
| 1397. |
For the non-catalytic reaction of particles with surrounding fluid, the time needed to achieve the same fractional conversion for particles of different but unchanging sizes is proportional to the square of particle diameter, when the __________ is the controlling resistance. |
| A. | Film diffusion |
| B. | Diffusion through ash layer |
| C. | Chemical reaction |
| D. | Either (A), (B) or (C) |
| Answer» C. Chemical reaction | |
| 1398. |
__________ gas is normally employed in B.E.T. method of finding out the surface area of catalyst. |
| A. | N2 |
| B. | H2 |
| C. | CO2 |
| D. | He |
| Answer» B. H2 | |
| 1399. |
A first order gaseous phase reaction is catalysed by a non-porous solid. The kinetic rate constant and the external mass transfer co-efficients are k and kg respectively. The effective rate constant (keff) is given by |
| A. | ke ff = k + kg |
| B. | ke ff = (k+ kg)/2 |
| C. | ke ff = (kkg) 1/2 |
| D. | 1/ke ff = 1/k + 1/kg |
| Answer» E. | |
| 1400. |
What is the dispersion number for a CSTR? |
| A. | 0 |
| B. | 1 |
| C. | < 1 |
| D. | ∞ |
| Answer» E. | |