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.
| 551. |
_ During manufacture of H‚ÇÇSO‚ÇÑ, the oxidation of SO‚ÇÇ to SO‚ÇÉ by oxygen is an en- dothermic reaction. The yield of SO‚ÇÉ will be maximised, if the$? |
| A. | Temperature is increased |
| B. | Pressure is reduced |
| C. | Temperature is increased and pressure is reduced |
| D. | Temperature is reduced and pressure is increased |
| Answer» E. | |
| 552. |
_ The following gas phase reactions are carried out isothermally in a CSTR.A → 2R ; r₁ = K₁pA ;K₁ = 20mole/(sec.m³ bar)A → 3S ; r₂ = K₂ pA ;K₂ = 40mole/ (sec.m³ .bar)What is the maximum possible value of FR(mole/sec.) ?$? |
| A. | 1/3 |
| B. | 1/2 |
| C. | 2/3 |
| D. | 2 |
| Answer» D. 2 | |
| 553. |
_ BET apparatus is used to determine the$? |
| A. | Specific surface of a porous catalyst |
| B. | Pore size distribution |
| C. | Pore diameter |
| D. | Porosity of the catalyst bed |
| Answer» B. Pore size distribution | |
| 554. |
_ Mean residence time is equal to the space time, when$? |
| 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 of the above |
| Answer» E. | |
| 555. |
_ A typical example of an exothermic reversible reaction conducted at high pressure in industry is$? |
| A. | Dehydration of ethanol |
| B. | Methanol synthesis |
| C. | Reformation of methane |
| D. | Polymerisation of ethylene |
| Answer» B. Methanol synthesis | |
| 556. |
_ From among the following, choose one which is not an exothermic process.$? |
| A. | Methanol synthesis |
| B. | Catalytic cracking |
| C. | Ammonia synthesis |
| D. | Oxidation of sulphur |
| Answer» C. Ammonia synthesis | |
| 557. |
_ The catalytic activity of enzymes is due to their capacity to lower the __________ energy.$? |
| A. | Activation |
| B. | Potential |
| C. | Kinetic |
| D. | None of these |
| Answer» B. Potential | |
| 558. |
_ Half life period of decomposition of a liquid 'A' by irreversible first order reaction is 12 minutes. The time required for 75% conversion of 'A' is __________ minutes.$? |
| A. | 18 |
| B. | 24 |
| C. | 6 |
| D. | 12 |
| Answer» C. 6 | |
| 559. |
_ The catalyst in a second order reversible reaction increases the rate of the forward reaction$? |
| A. | And decreases that of backward reaction |
| B. | And backward reaction equally |
| C. | Only |
| D. | To a greater extent than that of the backward reaction |
| Answer» C. Only | |
| 560. |
_ The rate constant of a first order reaction depends on the$? |
| A. | Concentration of the reactant |
| B. | Temperature |
| C. | Concentration of the product |
| D. | Time |
| Answer» C. Concentration of the product | |
| 561. |
_ If 'n' is the order of reaction, then unit of rate constant is$? |
| A. | 1/(time)(concentration)n - 1 |
| B. | (time)-1 (concentration)n - 1 |
| C. | (time)n - 1 (concentration) |
| D. | None of these |
| Answer» B. (time)-1 (concentration)n - 1 | |
| 562. |
_ For the reaction, A + B ‚Üí 2B + C,$? |
| A. | rA = rB |
| B. | rA = -rB |
| C. | rA = 2rB |
| D. | rA = rB/2 |
| Answer» C. rA = 2rB | |
| 563. |
_ In an ideal tubular-flow reactor$? |
| A. | There is no mixing in longitudinal direction |
| B. | Mixing takes place in radial direction |
| C. | There is a uniform velocity across the radius |
| D. | All of the above |
| Answer» E. | |
| 564. |
_ A trickle bed reactor is the one, which$? |
| A. | Has altogether three streams either entering or leaving |
| B. | Processes three reactants at different flow rates |
| C. | Processes three reactants with same flow rate |
| D. | Employs all the three phases (i.e.. .solid, liquid and gas) |
| Answer» E. | |
| 565. |
_ An isothermal aqueous phase reversible reaction, P ⇋ R, is to be carried out in a mixed flow reactor. The reaction rate in k.mole/m³ .h is given by, r = 0.5CP - 0.125CR. A stream containing only P enters the$? |
| A. | 0.80 |
| B. | 1.33 |
| C. | 1.60 |
| D. | 2.67 |
| Answer» D. 2.67 | |
| 566. |
__For a homogeneous reaction of nth order, the dimension of the rate constant is given by__ |
| A. | L/(time)n |
| B. | (concentration)1 - n/(time) |
| C. | (concentration)n - 1/(time) |
| D. | None of these |
| Answer» C. (concentration)n - 1/(time) | |
| 567. |
__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 | |
| 568. |
__The gas phase reaction 2A ‚Äö√°√£ 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 | |
| 569. |
__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 no. of moles |
| Answer» D. Gas reactions with changing no. of moles | |
| 570. |
__To maximise the formation of R in the simultaneous reactionA + B ‚Üí R , rR = 2CA0.5.CB2 A + B ‚Üí S , rS = 1.5 CA . CB We should have__ |
| A. | Low CA, low CB |
| B. | Low CA, high CB |
| C. | High CA, low CB |
| D. | High CA, high CB |
| Answer» C. High CA, low CB | |
| 571. |
__A Catalyst__ |
| A. | Increases the equilibrium concentration of the product |
| B. | Changes the equilibrium constant of the reaction |
| C. | Shortens the time to reach the equilibrium |
| D. | None of these |
| Answer» D. None of these | |
| 572. |
__In a first order reaction, the time required to reduce the concentration of reactant from 1 mole/litre to 0.5 mole/litre will be __________ that required to reduce it from 10 moles/litre to 5 moles/litre in the same volume.__ |
| A. | More than |
| B. | Less than |
| C. | Same as |
| D. | Data insufficient; can't be predicted |
| Answer» D. Data insufficient; can't be predicted | |
| 573. |
__Inversion of cane sugar is an example of__ |
| A. | Unimolecular reaction with first order |
| B. | Bimolecular reaction with second order |
| C. | Bimolecular reaction with first order |
| D. | Unimolecular reaction with second order |
| Answer» D. Unimolecular reaction with second order | |
| 574. |
__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 | |
| 575. |
__The rate constant of a chemical reaction decreases by decreasing the__ |
| A. | Pressure |
| B. | Concentration of reactants |
| C. | Temperature |
| D. | Duration of reaction |
| Answer» D. Duration of reaction | |
| 576. |
__In a/an __________ vessel, the fluid enters and leaves following plug flow.__ |
| A. | Open |
| B. | Closed |
| C. | Open-closed |
| D. | Close-opened |
| Answer» C. Open-closed | |
| 577. |
__Rate constant 'k' and absolute temperature 'T' are related by collision theory (for bimolecular) as__ |
| A. | k ‚Äö√ √π T1.5 |
| B. | k ‚Äö√ √π exp(-E/RT) |
| C. | k ‚à ù ‚à öT |
| D. | k ‚Äö√ √π T |
| Answer» D. k ‚Äö√ √π T | |
| 578. |
__For a zero order chemical reaction, the__ |
| A. | Half life period is directly proportion to the initial concentration of the reac-tants |
| B. | Plot of products concentration with time is a straight line through the origin |
| C. | Products concentration increases linerarly with time |
| D. | All of the above |
| Answer» E. | |
| 579. |
__According to Arhenious equation of temperature dependency of rate constant for an elementary reaction__ |
| A. | K ‚à ù ‚à öT |
| B. | K ‚Äö√ √π e-E/RT |
| C. | K ‚Äö√ √π T e-E/RT |
| D. | None of these |
| Answer» C. K ‚Äö√ √π T e-E/RT | |
| 580. |
__On application of pressure to the equilibrium system, ice ‚Äö√°√£ water; which of the following phenomenon will occur?__ |
| A. | Water will evaporate |
| B. | Equilibrium will not be attained |
| C. | More ice will be formed |
| D. | More water will be formed |
| Answer» E. | |
| 581. |
__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 | |
| 582. |
__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 | |
| 583. |
__A balanced chemical reaction equation conforms to the law of__ |
| A. | Conservation of mass |
| B. | Avagadro's hypothesis |
| C. | Gaseous volumes |
| D. | None ofthese |
| Answer» B. Avagadro's hypothesis | |
| 584. |
__A pulse tracer is introduced in an ideal CSTR (with a mean residence time ι) at time, t = 0. The time taken for the exit concentration of the tracer to reach half of its initial value will be__ |
| A. | 2τ |
| B. | 0.5τ |
| C. | τ/0.693 |
| D. | 0.693τ |
| Answer» B. 0.5≈ì√ë | |
| 585. |
__With increase in temperature, the equilibrium conversion of a reversible exothermic reaction__ |
| A. | Decreases |
| B. | Increases |
| C. | Remains unaffected |
| D. | Decreases linearily with temperature |
| Answer» B. Increases | |
| 586. |
__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 | |
| 587. |
__The catalytic converter for conversion of SO‚ÇÇ to SO‚ÇÉ by contact process should have a feed with SO‚ÇÇ content between__ |
| A. | 2-5% |
| B. | 7-10% |
| C. | 12-15% |
| D. | 20-25% |
| Answer» C. 12-15% | |
| 588. |
__Carrier in a catalyst increases its__ |
| A. | Surface area |
| B. | Activity |
| C. | Performance |
| D. | None of these |
| Answer» B. Activity | |
| 589. |
_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 | |
| 590. |
_A space velocity of 5 hr⁻¹ means that$? |
| A. | Five reactor volumes of feed (at specified conditions) are being fed into the reactor per hour |
| B. | After every 5 hours, reactor is being filled with the feed |
| C. | Cent per cent conversion can be achieved in at least 5 hours |
| D. | A fixed conversion of a given batch of feed takes 5 hours |
| Answer» B. After every 5 hours, reactor is being filled with the feed | |
| 591. |
_Reaction rate of a first order reaction, which is half completed in 23 minutes will be$? |
| A. | 0.03 sec⁻¹ |
| B. | 0.03 min⁻¹ |
| C. | 0.03 hr⁻¹ |
| D. | 0.05 min⁻¹ |
| Answer» C. 0.03 hr‚Äö√Ö¬™¬¨œÄ | |
| 592. |
_In case of physical adsorption, the heat of adsorption is of the order of __________ kcal/kg.mole.$? |
| A. | 100 |
| B. | 1000 |
| C. | 10000 |
| D. | 100000 |
| Answer» C. 10000 | |
| 593. |
_Rate of a chemical reaction is not influenced by the$? |
| A. | Catalyst |
| B. | Temperature |
| C. | Reactants concentration |
| D. | Number of molecules of reactants taking part in a reaction |
| Answer» E. | |
| 594. |
_The ratio of moles of a reactant converted into the desired product to that converted into unwanted product is called$? |
| A. | Operational yield |
| B. | Relative yield |
| C. | Selectivity |
| D. | None of these |
| Answer» D. None of these | |
| 595. |
_The 'E' curve for a non-ideal reactor defines the fraction of fluid having age between t and t + dt$? |
| A. | At the inlet |
| B. | At the outlet |
| C. | In the reactor |
| D. | Averaged over the inlet and outlet |
| Answer» C. In the reactor | |
| 596. |
_For identical flow rate, feed composition and for elementary first order reactions, 'N' equal sized mixed reactors in series with a total volume 'V' gives the same conversion as a single plug flow reactor of volume 'V' for constant density systems. This is true, when the value of 'N' is$? |
| A. | 1 |
| B. | >1 |
| C. | ‚à û |
| D. | ‚â•1 |
| Answer» D. ‚Äö√¢‚Ä¢1 | |
| 597. |
_The dispersion number of perfect mixed flow is$? |
| A. | 0 |
| B. | > 150 |
| C. | ‚à û |
| D. | < 2100 |
| Answer» D. < 2100 | |
| 598. |
_The reactions of high molecularity are rare, because$? |
| A. | Of very large activation energy of many bodies |
| B. | Of low probability of many body collisions |
| C. | Many body collisions are not favoured energetically |
| D. | Of requirement of very large concentration for such reactions |
| Answer» C. Many body collisions are not favoured energetically | |
| 599. |
_What is the dispersion number for a plug flow reactor?$? |
| A. | 0 |
| B. | ? |
| C. | 1 |
| D. | -1 |
| Answer» B. ? | |
| 600. |
_The reaction in which the rate equation corresponds to a stoichiometric equation, is called a/an __________ reaction.$? |
| A. | Elementary |
| B. | Non-elementary |
| C. | Parallel |
| D. | Autokinetic |
| Answer» B. Non-elementary | |