chemical engineering Mcqs
3151. Carbon percentage (by weight) in crude petroleum may be about_________________?
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A. 65

B. 95

C. 85

D. 75

3152. With increase in temperature, the equilibrium _______________ rises in case of endothermic reaction?
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A. Constant

B. Conversion

C. Both A. & B.

D. Neither A. nor B.

3153. The experimentally determined overall order of the reaction, A + B ? C + D, is two. Then the__________________?
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A. Reaction may be elementary with molecularity of 2

B. Reaction is elementary with a molecularity of 2

C. Reaction is elementary but the molecularity may not be 2

D. Molecularity of the reaction is 2, but the reaction may not be elementary

3154. For an ideal plug flow reactor, the value of Peclet number is_______________?
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A. 10

B. 0

C. 1

D. ?

3155. A Catalyst ____________________?
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A. Increases the equilibrium concentration of the product

B. Shortens the time to reach the equilibrium

C. Changes the equilibrium constant of the reaction

D. None of these

3156. Mercaptans is represented as (where R and R are alkyl groups) _____________________?
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A. R-S-R

B. R-COOH

C. R-S-R

D. R-S-H
3157. Gasoline extracted from natural gas (by compression and cooling) is called the ___________ gasoline?
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A. Polymer

B. Casing head

C. Unleaded

D. Straight run

3158. The main use of heavy gas oil produced by the vacuum distillation unit is as a_____________________?
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A. Feedstock for fluid catalytic cracking unit

B. Blending component for kerosene

C. Blending component for petrol

D. None of these

3159. BET apparatus_______________________?
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A. None of these

B. Operates at very high pressure

C. Measures the catalyst surface area directly

D. Is made entirely of stainless steel

3160. The reactions of high molecularity are rare, because________________?
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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

3161. The conductivity of crude oil-water mixture depends on the__________________?
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A. Temperature

B. All A., B. and C.

C. Water percentage

D. pH value

3162. For a heterogeneous catalytic reaction____________________?
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A. The surface of the catalyst does not play an important role during reaction

B. end of reaction</strong>

C. ch does not mean that catalyst concentration is important

D. A relatively small amount of catalyst can cause the conversion of large amount of reactants

E. Free energy of activation is lowered in the presence of catalyst, which remains unchanged at

F. The catalyst does not form an intermediate complex with the reactant

3163. The rate equation for the reaction represented by as shown in the bellow figure, is given by rx = K1 . Cx/(1 + K2 Cx). At high value of Cx (i.e.., K2Cx > > 1), the order of the reaction and the rate constant are respectively___________________?
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A. First order & K1/K2

B. First order & K1

C. Zero order & K1

D. Zero order & K1/K2
3164. Rate constant for a first order reaction does not depend upon reaction time, extent of reaction and the initial concentration of reactants; but it is a function of reaction temperature. In a chemical reaction, the time required to reduce the concentration of reactant from 100 gm moles/litre to 50 gm moles/litre is same as that required to reduce it from 2 gm moles/litre to 1 gm mole/litre in the same volume. Then the order of this reaction is ?
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A. 1

B. 3

C. 0

D. 2

3165. For high conversion in a highly exothermic solid catalysed reaction, use a ______________ bed reactor?
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A. Fluidised

B. Fixed bed reactor followed by a fluidised

C. Fixed

D. Fluidised bed reactor followed by a fixed
3166. In a/an ______________ reactor, there is exchange of heat with the surroundings with sizeable temperature variation?
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A. Adiabatic

B. Non-adiabatic

C. Isothermal

D. None of these

3167. The rate controlling step for the heterogeneous irreversible catalytic reaction A(g) + B(g) ? C(g) is the surface reaction of absorbed A with absorbed B to give adsorbed C. The rate expression for this reaction can then be written as (where, KA, KB and KC are the equilibrium constants and is the rate constant of the rate controlling step) ?
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A. k KAKB pApB / (1 + KApA + KBpB + KCpC)2

B. k KAKB pApB / (1 + KApA + KBpB)

C. k KAKB pApB / (1 + KApA + KBpB + KCpC)

D. k KA pApB / (1 + KApA + KBpB)

3168. The ratio of moles of a reactant converted into the desired product to that converted into unwanted product is called_________________?
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A. None of these

B. Relative yield

C. Selectivity

D. Operational yield

3169. For a gaseous phase reaction, rate of reaction is equal to K. CA . CB. If the volume of the reactor is suddenly reduced to 1/4th of its initial volume, then the rate of reaction compared to the original rate will be ______________ times?
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A. 8-Jan

B. 16-Jan

C. 16

D. 8

3170. Which of the following does not require preheating during storage in the storage tank as well as during atomisation through burners ?
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A. PCM

B. Tar

C. Low viscosity furnace oil

D. Light diesel oil
3171. From among the following, choose one which is not an exothermic process ?
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A. Ammonia synthesis

B. Catalytic cracking

C. Methanol synthesis

D. Oxidation of sulphur

3172. When the reaction is dominated by intraparticle diffusion, the apparent order of reaction (nD) as measured is related to the true order (n) as ________________?
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A. nD = n + 1

B. None of these

C. nD = n/2

D. nD = (n + 1)/2
3173. Pure ethanol vapor is fed to a reactor packed with alumina catalyst, at the rate of 100 kmole / hr. The reactor products comprise: ethylene: 95 kmole / hr, water vapour: 97.5 k mole / hr and diethyl ether: 2.5 kmole/hr. The reactions occuring can be represented by: C2H5OH ? C2H4 + H2O 2C2H5OH ? C2H5 O C2H5 + H2O The percent conversion of ethanol in the reactor is________________?
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A. 2.5

B. 100

C. 95

D. 97.5

3174. If in the gaseous phase reaction, N2O4 ? 2NO2, x is the part of N2O4 which dissociates, then the number of molecules at equilibrium will be___________________?
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A. (1 x)

B. (1 x)2

C. (1 + x)

D. (1 + x)2

3175. With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion)?
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A. Decreases

B. Remain same

C. Increases linearly

D. Increases
3176. A reaction in which one of the products of reaction acts as a catalyst is called a/an ______________ reaction?
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A. Catalytic

B. Autocatalytic

C. Photochemical

D. None of these

3177. True vapour pressure of a petroleum fraction ________________ Reid vapour pressure?
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A. Is less than

B. Is same as

C. Is more than

D. May be either more or less than
3178. In an ideal tubular-flow reactor_________________?
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A. There is a uniform velocity across the radius

B. There is no mixing in longitudinal direction

C. All A., B. and C.

D. Mixing takes place in radial direction

3179. Refractive index of a petrofuel which is the ratio of velocity of light in air to its velocity in the petrofuel gives an indication if its_________________?
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A. Molecular weight

B. Aromatics content

C. Both A. & B.

D. Neither a nor b

3180. Glycol added to petrol acts as a/an ________________ agent ?
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A. Dewaxing

B. Anti-knocking

C. Anti-icing

D. Anti-gum forming

3181. A batch adiabatic reactor at an initial temperature of 373K is being used for the reaction, A ? B. Assume the heat of reaction is 1kJ/mole at 373K and heat capacity of both A and B to be constant and equal to 50J/mole.K. The temperature rise after a conversion of 0.5 will be ____________?
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A. 20C

B. 5C

C. 100C

D. 10C
3182. A batch reactor is suitable for__________________?
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A. Obtaining uniform polymerisation products in highly exothermic reactions

B. Achieving cent percent conversion of reactants into products

C. Large scale gaseous phase reactions

D. Liquid phase reactions
3183. The energy balance equation over a tubular reactor under transient conditions is________________?
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A. A linear partial differential equation

B. An ordinary non-linear differential equation

C. A non-linear partial differential equation

D. An algebraic differential equation

3184. ______________ is the response curve for a step input signal from a reactor ?
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A. S-curve

B. C-curve

C. I-curve

D. None of these

3185. The half life period of a first order reaction is given by (where, K = rate constant) ?
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A. 2.5 K

B. 0.693/K

C. 1.5 K

D. 6.93 K

3186. A photochemical reaction is _______________?
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A. Catalysed by light

B. Accompanied with emission of light

C. Initiated by light

D. All A., B. & C.

3187. Catalyst used in the catalytic polymerisation is__________________?
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A. Aluminium chloride

B. Nickel

C. Phosphoric acid on kieselguhr

D. Vanadium pentoxide

3188. LPG when brought to atmospheric pressure & temperature will be a________________?
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A. Gas lighter than air

B. Liquid heavier than water

C. Liquid lighter than water

D. Gas heavier than air
3189. Pick out the wrong statement ?
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A. In general, the rate of a reaction becomes triple for every 10C rise in temperature

B. In a multistep reaction, the slowest step is the rate determining step

C. Molecularity of a reaction cannot be zero but the order of a reaction can be zero

D. Slow chemical reactions have generally high values of activation energy

3190. Which of the following is the easiest to crack ?
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A. Naphthenes

B. Aromatics

C. Olefins

D. Paraffins
3191. Which of the following is not an important property of fuel oil/furnace oil ?
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A. Aniline point

B. Viscosity

C. Sulphur content

D. Flash point

3192. For the chemical reaction X ? Y, it is observed that, on doubling the concentration of X, the reaction rate quadruples. If the reaction rate is proportional to Cx n, then what is the value of n? ?
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A. 4

B. 4-Jan

C. 2

D. 16

3193. Maximum sulphur percentage in low sulphur heavy stock (LSHS) furnace oil is about_________________?
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A. 3.5

B. 2.5

C. 1

D. 0.1

3194. A catalyst______________________?
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A. Is capable of reacting with any one of the reactants

B. Initiates a reaction

C. Cannot be recovered chemically unchanged at the end of a chemical reaction

D. Lowers the activation energy of reacting molecules
3195. There is no correspondence between stoichiometric and the rate equation in case of a/an _____________ reaction?
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A. Multiple

B. Elementary

C. Autocatalytic

D. Non-elementary
3196. Char value of Kerosene is the amount of charred oil deposition on the wick obtained after burning it in a standard wick lamp at a standard rate for 24 hours. Char value of a good quality kerosene should be less than ________________ mg/kg of kerosene?
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A. 1

B. 20

C. 100

D. 500

3197. The rate constant of a chemical reaction decreases by decreasing the____________________?
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A. Concentration of reactants

B. Duration of reaction

C. Temperature

D. Pressure

3198. The units of frequency factor in Arrhenius equation_________________?
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A. Are cycles per unit time

B. Are the same as those of the rate constant

C. Depend on temperature, pressure etc. of the reaction

D. Depend on the order of the reaction

3199. 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?
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A. Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1

B. Inner catalyst core of radius R/8 does not participate in reaction

C. Inner catalyst core of radius 7R/8 does not participate in reaction

D. Inner catalyst core of radius R/2 does not participate in reaction

3200. Thermodynamic equilibrium constant in a system is affected by___________________?
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A. All A., B. & C.

B. Inerts

C. Temperature

D. Pressure