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.
| 351. |
An imbalanced chemical reaction equation is against the law of________________? |
| A. | Multiple proportion |
| B. | Conservation of mass |
| C. | Constant proportion |
| D. | None of these |
| Answer» C. Constant proportion | |
| 352. |
An exothermic reaction takes place in an adiabatic reactor. The product temperature ______________ reactor feed temperature? |
| A. | Is always equal to |
| B. | Is always greater than |
| C. | Is always less than |
| D. | May be greater or less than |
| Answer» C. Is always less than | |
| 353. |
An example of autothermal reactor operation is______________________? |
| A. | Sulphur dioxide oxidation |
| B. | Ethylene oxidation |
| C. | Benzene oxidation |
| D. | Ammonia synthesis |
| Answer» C. Benzene oxidation | |
| 354. |
An endothermic second order reaction is carried out in an adiabatic plug flow reactor. The rate of heat generation is ___________________? |
| A. | Maximum at the inlet of the reactor |
| B. | Maximum at the exit of the reactor |
| C. | Maximum at the centre of the reactor |
| D. | Constant throughout the reactor |
| Answer» B. Maximum at the exit of the reactor | |
| 355. |
An endothermic aqueous phase first order irreversible reaction is carried out in an adiabatic plug flow reactor. The rate of reaction ? |
| A. | Is maximum at the inlet of the reactor |
| B. | Goes through a maximum along the length of the reactor |
| C. | Goes through a minimum along the length of the reactor |
| D. | Is maximum at the exit of the reactor |
| Answer» B. Goes through a maximum along the length of the reactor | |
| 356. |
An autothermal reactor is_________________? |
| A. | Most suitable for a second order reaction |
| B. | Most suitable for a reversible reaction |
| C. | Completely self-supporting in its thermal energy requirements |
| D. | Isothermal in nature |
| Answer» D. Isothermal in nature | |
| 357. |
According to the ‘law of mass action’, the rate of reaction is directly proportional to the__________________? |
| A. | Equilibrium constant |
| B. | Volume of the reaction vessel |
| C. | Nature of the reactants |
| D. | Molar concentration of the reactants |
| Answer» E. | |
| 358. |
According to Arrhenius equation of temperature dependency of rate constant for an elementary reaction _________________? |
| A. | k ∝ √T |
| B. | k ∝ e-E/RT |
| C. | k ∝ T e-E/RT |
| D. | None of these |
| Answer» C. k ∝ T e-E/RT | |
| 359. |
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 | |
| 360. |
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. | |
| 361. |
A stirred tank reactor compared to tubular-flow reactor provides____________________? |
| A. | More uniform operating conditions |
| B. | Permits operation at the optimum temperature for a long reaction time |
| C. | Higher overall selectivity for a first order consecutive reaction |
| D. | All A., B. and C. |
| Answer» E. | |
| 362. |
A spherical porous catalyst particle of radius R is subjected to reactant A which reacts to form B by a zero order surface reaction A → B. Film mass transfer resistance is negligible and pore diffusion of A is rate controlling. The effectiveness factor of the catalyst is reported as 7/8. Which of the following statement is true? |
| A. | Inner catalyst core of radius R/8 does not participate in reaction |
| B. | Inner catalyst core of radius R/2 does not participate in reaction |
| C. | Inner catalyst core of radius 7R/8 does not participate in reaction |
| D. | Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1 |
| Answer» B. Inner catalyst core of radius R/2 does not participate in reaction | |
| 363. |
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 | |
| 364. |
A space time of 3 hours for a flow reactor means that___________________? |
| A. | The time required to process one reactor volume of feed (measured at specified conditions) is 3 hours |
| B. | Three reactor volumes of feed can be processed every hour |
| C. | It takes three hours to dump the entire volume of the reactor with feed |
| D. | Conversion is cent per cent after three hours |
| Answer» B. Three reactor volumes of feed can be processed every hour | |
| 365. |
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. | |
| 366. |
A second order liquid phase reaction, A → B, is carried out in a mixed flow reactor operated in semi batch mode (no exit stream). The reactant A at concentration CAF is fed to the reactor at a volumetric flow rate of F. The volume of the reacting mixture is V and the density of the liquid mixture is constant. The mass balance for A is_______________________? |
| A. | d(VCA)/dt = -F (CAF – CA) – kCA2V |
| B. | d(VCA)/dt = F (CAF – CA) – kCA2V |
| C. | d(VCA)/dt = -FCA – kCA2V |
| D. | d(VCA)/dt = FCAF – kCA2V |
| Answer» E. | |
| 367. |
A rise in temperature ______________________? |
| A. | Normally tends to increase the reaction rate |
| B. | Does not affect a catalysed reaction |
| C. | Does not affect photo-chemical reaction rates |
| D. | All A., B. and C. |
| Answer» E. | |
| 368. |
A reversible liquid phase endothermic reaction is to be carried out in a plug flow reactor. For minimum reactor volume, it should be operated such that the temperature along the length ? |
| A. | Decreases |
| B. | Increases |
| C. | Is at the highest allowable temperature throughout |
| D. | First increases and then decreases |
| Answer» D. First increases and then decreases | |
| 369. |
A reactor is generally termed as an autoclave, when it is a_____________________? |
| A. | High pressure batch reactor |
| B. | Atmospheric pressure tank reactor |
| C. | High pressure tubular reactor |
| D. | Atmospheric pressure CSTR |
| Answer» B. Atmospheric pressure tank reactor | |
| 370. |
A reaction which is catalysed by an acid is also catalysed by any substance, which has a tendency to _________________? |
| A. | Lose a proton |
| B. | Gain a proton |
| C. | Lose an electron |
| D. | None of these |
| Answer» B. Gain a proton | |
| 371. |
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 | |
| 372. |
A reaction in which one of the products of reaction acts as a catalyst is called a/an ______________ reaction? |
| A. | Catalytic |
| B. | Autocatalytic |
| C. | Photochemical |
| D. | None of these |
| Answer» C. Photochemical | |
| 373. |
A pulse tracer is introduced in an ideal CSTR (with a mean residence time I) at time, t = 0. The time taken for the exit concentration of the tracer to reach half of its initial value will be__________________? |
| A. | 2η |
| B. | 0.5η |
| C. | η/0.693 |
| D. | 0.693η |
| Answer» B. 0.5η | |
| 374. |
A pollutant P degrades according to first order kinetics. An aqueous stream containing P at 2 kmole/m3 and volumetric flow rate 1m3 /h requires a mixed flow reactor of volume V to bring down the pollutant level to 0.5 kmole/m3. The inlet concentration of the pollutant is now doubled and the volumetric flow rate is tripled. If the pollutant level is to be brought down to the same level of 0.5 k.mole/m3, the volume of the mixed flow reactor should be increased by a factor of_______________? |
| A. | 7 |
| B. | 6 |
| C. | 3 |
| D. | 7/3 |
| Answer» B. 6 | |
| 375. |
A plug-flow reactor is characterized by _____________________? |
| A. | High capacity |
| B. | Presence of axial mixing |
| C. | Presence of lateral mixing |
| D. | Constant composition and temperature of reaction mixture |
| Answer» D. Constant composition and temperature of reaction mixture | |
| 376. |
A photochemical reaction is _______________? |
| A. | Accompanied with emission of light |
| B. | Catalysed by light |
| C. | Initiated by light |
| D. | All A., B. & C. |
| Answer» D. All A., B. & C. | |
| 377. |
A photochemical reaction is _______________ light? |
| A. | Initiated by |
| B. | Accompanied with emission of |
| C. | Catalysed by |
| D. | Used to convert heat energy into |
| Answer» B. Accompanied with emission of | |
| 378. |
A non-catalytic chemical reaction of the type as shown in the bellow figure is called a _____________ reaction? |
| A. | Parallel |
| B. | Series |
| C. | Series-parallel |
| D. | None of these |
| Answer» D. None of these | |
| 379. |
A multiple reaction may be classified as a ________________ reaction? |
| A. | Consecutive or side |
| B. | Parallel or side |
| C. | Mixed |
| D. | All A., B. and C. |
| Answer» E. | |
| 380. |
A liquid decomposes by irreversible first order kinetics and the half life period of this reaction is 8 minutes. The time required for 75% conversion of the liquid will be ____________________ minutes? |
| A. | 4 |
| B. | 8 |
| C. | 12 |
| D. | 16 |
| Answer» E. | |
| 381. |
A high space velocity means that a given__________________? |
| A. | Reaction can be accomplished with small reactor |
| B. | Conversion can be obtained with a high feed rate |
| C. | Both A. and B. |
| D. | None of these |
| Answer» D. None of these | |
| 382. |
A gaseous reactant is introduced in a mixed reactor of 3 litres volume at the rate of 1 litre/second. The space time is ______________ seconds? |
| A. | 1 |
| B. | 3 |
| C. | 1/3 |
| D. | 32 |
| Answer» C. 1/3 | |
| 383. |
A first order reaction requires two equal sized CSTR. The conversion is____________________? |
| A. | Less when they are connected in series |
| B. | More when they are connected in series |
| C. | More when they are connected in parallel |
| D. | Same whether they are connected in series or in parallel |
| Answer» C. More when they are connected in parallel | |
| 384. |
A first order reaction is to be treated in a series of two mixed reactors. The total volume of the two reactors is minimum, when the reactors are_____________________? |
| A. | Equal in size |
| B. | Of different sizes |
| C. | Of such size that the ratio of their volumes is < 5 |
| D. | None of these |
| Answer» B. Of different sizes | |
| 385. |
A first order reaction A → B occurs in an isothermal porous catalyst pellet of spherical shape. If the concentration of A at the centre of the pellet is much less than at the external surface, the process is limited by__________________? |
| A. | Diffusion within the pellet |
| B. | Reaction |
| C. | External mass transfer |
| D. | None of the above |
| Answer» B. Reaction | |
| 386. |
A first order irreversible reaction, A → B is carried out separately in a constant volume as well as in a variable volume reactor for a particular period. It signifies that _____________ in the two reactors? |
| A. | Both conversion as well as concentration are same |
| B. | Conversion in both will be the same but concentrations will be different |
| C. | Both the conversion as well as concentrations will be different |
| D. | None of these |
| Answer» C. Both the conversion as well as concentrations will be different | |
| 387. |
A first order homogeneous reaction of the type X → Y → Z (consecutive reaction) is carried out in a CSTR. Which of the following curves respectively show the variation of the concentration of X, Y and Z with time ? |
| A. | I, II, III |
| B. | III, II, I |
| C. | III, I, II |
| D. | II, III, I |
| Answer» C. III, I, II | |
| 388. |
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. | keff = k + kg |
| B. | keff = (k+ kg)/2 |
| C. | keff = (kkg)1/2 |
| D. | 1/keff = 1/k + 1/kg |
| Answer» E. | |
| 389. |
A CSTR is to be designed in which an exothermic liquid phase first order reaction of the type, A → R, is taking place. The reactor is to be provided with a jacket in which coolant is flowing. Following data is given: CA0= 5 kmole/m3; XA = 0.5; Feed temperature = reactor temperature = 40°C. Rate constant at 40°C = 1 min-1; (ΔH) = – 40kJ/mole; ρ = 1000kg/m3 CP = 4 J/gm.°C ; q = 10-3 m3/min (ρ and CP are same for the reactant and product streams). The amount of heat to be removed is_________________? |
| A. | 2/3 kW |
| B. | 1 kW |
| C. | 5/3 kW |
| D. | 4 kW |
| Answer» D. 4 kW | |
| 390. |
A chemical reaction occurs, when the energy of the reacting molecules is ________________ the activation energy of reaction? |
| A. | Less than |
| B. | Equal to |
| C. | More than |
| D. | Equal to or more than |
| Answer» E. | |
| 391. |
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. | |
| 392. |
A chemical reaction is of zero order, when the reaction rate is (where, CA = concentration of reactant) ? |
| A. | ∝ CA |
| B. | ∝ 1/CA |
| C. | Independent of temperature |
| D. | None of these |
| Answer» E. | |
| 393. |
A chemical reaction, A → 3B, is conducted in a constant pressure vessel. Starting with pure A, the volume of the reaction mixture increases 3 times in 6 minutes. The fractional conversion is ___________________? |
| A. | 0.33 |
| B. | 0.5 |
| C. | 1 |
| D. | Data insufficient, can’t be predicted |
| Answer» D. Data insufficient, can’t be predicted | |
| 394. |
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 | |
| 395. |
A catalyst______________________? |
| A. | Initiates a reaction |
| B. | Lowers the activation energy of reacting molecules |
| C. | Is capable of reacting with any one of the reactants |
| D. | Cannot be recovered chemically unchanged at the end of a chemical reaction |
| Answer» C. Is capable of reacting with any one of the reactants | |
| 396. |
A catalyst loses its activity due to__________________? |
| A. | Loss in surface area of the active component |
| B. | Agglomeration of metal particles caused by thermal sintering of the solid surface |
| C. | Covering of the catalytic active sites by a foreign substance |
| D. | All A., B. and C. |
| Answer» E. | |
| 397. |
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. | |
| 398. |
A catalyst is said to be a negative catalyst, if it ___________________? |
| A. | Retards the rate of reaction |
| B. | Reduces the value of equilibrium constant |
| C. | Does not initiate the reaction |
| D. | All A., B. and C. |
| Answer» B. Reduces the value of equilibrium constant | |
| 399. |
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 | |
| 400. |
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. | |