chemical engineering Mcqs
3001. Which one is used to determine the colour of petroleum products ?
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A. Saybolt chromometer

B. None of these

C. Colour comparator

D. Cleveland apparatus

3002. ____________ is the controlling step in a highly temperature sensitive fluid-solid non-catalytic reaction ?
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A. Chemical reaction

B. Ash diffusion

C. Gas film diffusion

D. None of these

3003. The most important property for a jet fuel is its________________?
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A. Flash point

B. Viscosity

C. Freezing point

D. Calorific value

3004. Concentration of H2SO4 catalyst in alkylation is kept between 90-98%, because H2SO4 having concentration?
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A. Less than 90% promotes polymerisation

B. More than 98% promotes cracking

C. Both A. and B.

D. Neither A. nor B.

3005. For a mixed flow reactor operating at steady state, the rate of reaction is given by______________?
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A. #NAME?

B. (FA0/V) (dCA/dt)

C. (FA0/V) + (dCA/dt)

D. (FA0/V) XA
3006. Flash point of diesel/kerosene (>50C) is determined by the_______________?
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A. Abel apparatus

B. Pensky-Martens apparatus

C. None of these

D. Saybolt chromometer

3007. Which of the following has the minimum API gravity of all ?
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A. Kerosene

B. Diesel

C. Petrol

D. Furnace oil
3008. In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for________________?
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A. Fast reactions in catalyst of small pore diameter

B. Slow reactions in catalyst of small pore diameter

C. Slow reactions in catalyst of large pore diameter

D. Fast reaction in catalyst of large pore diameter

3009. An endothermic aqueous phase first order irreversible reaction is carried out in an adiabatic plug flow reactor. The rate of reaction ?
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A. Goes through a minimum along the length of the reactor

B. Goes through a maximum along the length of the reactor

C. Is maximum at the exit of the reactor

D. Is maximum at the inlet of the reactor
3010. The eddy diffusivity for a liquid in plug flow must be_________________?
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A. 0

B. 1

C. ?

D. Between 0 and 1

3011. Enzymes (a protein) are catalysts found in organisms. Its efficiency of catalysing a reaction is due to its capacity to lower the activation energy of the reaction. The enzyme ptyalin used for food digestion is present in ___________________?
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A. Gland

B. Blood

C. Saliva

D. Intestine

3012. Photochemical reaction rate does not depend significantly on temperature, because____________________?
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A. None of these

B. It is a reversible reaction

C. The energy of reacting molecules exceeds the activation energy by absorption of light

D. It is an exothermic reaction

3013. Natural gas recovered along with crude oil from oil wells is called wet natural gas which has a higher ______________ compared to the dry natural gas?
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A. Quantity of propane

B. Unsaturated hydrocarbon content

C. Quantity of butane

D. Calorific value
3014. An exothermic reaction takes place in an adiabatic reactor. The product temperature ______________ reactor feed temperature?
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A. Is always less than

B. May be greater or less than

C. Is always equal to

D. Is always greater than
3015. An isothermal irreversible reaction is being carried out in an ideal tubular flow reactor. The conversion in this case will ______________ with decrease in space time?
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A. Decrease

B. Increase exponentially

C. Remain unchanged

D. Increase

3016. A multiple reaction may be classified as a ________________ reaction?
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A. Mixed

B. Parallel or side

C. Consecutive or side

D. All A., B. and C.
3017. For a first order reaction carried out in a plug flow reactor, the space time is__________________?
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A. (1/k) ln C/C0

B. k ln C0/C

C. k ln C/C0

D. (1/k) ln C0/C
3018. A balanced chemical reaction equation conforms to the law of________________?
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A. None of these

B. Gaseous volumes

C. Avogadros hypothesis

D. Conservation of mass
3019. Crude topping column operates at ________________ pressure?
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A. Vacuum

B. 3 atm

C. 10 atm

D. Atmospheric
3020. In case of a _____________ reactor, the composition in the reactor and at the exit of the reactor is the same ?
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A. Back-mix

B. Batch

C. Tubular

D. Semi-batch

3021. Considering the endothermic dissociation of CaCO3 in a closed vessel (CaCO3 ? CaO + CO2), the pressure of CO2 increases, if____________________?
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A. None of these

B. A catalyst is added

C. The temperature is increased

D. An inert gas is pumped keeping the temperature constant

3022. In a/an _____________ vessel, the fluid enters and leaves following plug flow?
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A. Open-closed

B. Closed

C. Close-opened

D. Open

3023. Antioxidants are added in petrol to _____________________?
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A. Prevent the lead build up in engines

B. Minimise the gum formation

C. Impart colour to it, for easy identification

D. Prevent icing of the carburettor

3024. In an ideal mixed reactor (at steady state), the ___________________?
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A. Exit stream has the same composition as the fluid within the reactor

B. All A., B. and C.

C. Space time is equivalent to holding time for constant density systems

D. Composition throughout the reactor remains same

3025. Sum of the powers of the concentration terms in the rate equation is called the _____________ of the reaction?
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A. Overall order

B. None of these

C. Order

D. Molecularity

3026. 1 centistoke is equal to ______________ Redwood I seconds?
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A. 1

B. 0.408

C. 4.08

D. 40.8

3027. The vacuum maintained in vacuum distillation unit for reduced crude is about _______________ mm Hg?
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A. 700

B. 120

C. 12

D. 1.2

3028. According to Arrhenius equation of temperature dependency of rate constant for an elementary reaction _________________?
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A. k ? T e-E/RT

B. k ? ?T

C. k ? e-E/RT

D. None of these

3029. The knowledge of initial concentration and rate constant is necessary to determine the half life time of a reaction of _______________ order?
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A. Second

B. First

C. None of these

D. Zero

3030. For an isothermal second order aqueous phase reaction, A ? B, the ratio of the time required for 90% conversion to the time required for 45% conversion is____________________?
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A. 4

B. 2

C. 22

D. 11
3031. At a given temperature, K1, K2 and K3 are equilibrium constants for the following reactions 1, 2, 3 respectively. CH4(g) + H2O(g) ? CO(g) + 3H2(g), CO(g) + H2O(g) ? CO2(g) + H2(g) CH4(g) + 2H2O(g) ? CO2(g) + 4H2(g) Then K1, K2 and K3 are related as ?
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A. K3(K1+K2)/2

B. K3 = K1.K2

C. K3 = (K1.K2)0.5

D. K3 = (K1.K2)2

3032. A first order reaction requires two unequal sized CSTR. Which of the following gives higher yield ?
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A. Large reactor followed by smaller one

B. Data insufficient, cant be predicted

C. Either of the arrangement A. or B. will give the same yield

D. Smaller reactor followed by larger one

3033. In case of _____________ reactions, the reaction rate does not decrease appreciably as the reaction proceeds?
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A. Parallel

B. Auto catalytic

C. Catalytic

D. Series

3034. N plug flow reactors in series with a total volume V gives the same conversion as a single plug flow reactor of volume V for _______________ order reactions?
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A. First

B. Third

C. Second

D. Any
3035. When all the limiting reactant is consumed in the reaction, the operational yield _______________ the relative yield?
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A. Equals

B. Is greater than

C. Can be either greater or smaller than (depends on the type of reaction)

D. Is smaller than

3036. An autothermal reactor is_________________?
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A. Completely self-supporting in its thermal energy requirements

B. Most suitable for a second order reaction

C. Most suitable for a reversible reaction

D. Isothermal in nature

3037. The rate of reaction of a/an ______________ reaction is not affected by temperature rise ?
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A. Zero order

B. Autocatalytic

C. Consecutive

D. Photochemical
3038. For the chemical reaction P ? Q, it is found that the rate of reaction doubles as the concentration of P is doubled. If the reaction rate is proportional to Cp n, then what is the value of n for this chemical reaction ?
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A. 3

B. 0

C. 2

D. 1
3039. Cracking is___________________?
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A. An exothermic reaction

B. None of these

C. Favoured at very low temperature

D. An endothermic reaction
3040. Reforming converts_________________?
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A. Olefins into paraffins

B. Naphthenes into paraffin

C. Naphthenes into olefins

D. Naphthenes into aromatics
3041. Reactions with high activation energy are_____________________?
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A. Very temperature sensitive

B. Always reversible

C. Always irreversible

D. Temperature insensitive

3042. In an exothermic chemical reaction, the reactants compared to the products have__________________?
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A. Same energy

B. Higher temperature

C. Less energy

D. More energy
3043. In which of the following gaseous phase reversible reactions, the product yield cannot be increased by the application of high pressure ?
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A. PCl3 + Cl2 ? PCl5

B. N + 3H2 ? 2NH3

C. 2SO2 + O2 ? 2SO3

D. N2 + O2 ? 2NO
3044. Clay treatment is used to remove ___________________ ?
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A. Salt from the crude oil

B. Wax from lube oil

C. Colour & dissolved gases from cracked gasoline

D. None of these

3045. Smoke point of a good burning kerosene may be around _______________ mm?
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A. 60-75

B. 0-5

C. 20-25

D. 100-120

3046. Velocity of a reaction depends upon the_________________?
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A. Nature of the reactants

B. Concentration of the reactants

C. Temperature at which the reaction is carried

D. All A., B. and C.
3047. Effective diffusivity (DE) in a catalyst pellet is related to molecular diffusivity (DN) and Knudsen diffusivity (DK) as_________________?
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A. DE = DN/DE

B. DE = DM . DE

C. DE = DM + DK

D. 1/DE = 1/DN + DK
3048. High aniline point of a petrofuel (say diesel) indicates that ________________?
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A. It has a very low diesel index

B. It is highly paraffinic in nature

C. Its ignition quality is very poor

D. It is highly aromatic in nature

3049. A catalyst loses its activity due to__________________?
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A. Covering of the catalytic active sites by a foreign substance

B. Loss in surface area of the active component

C. All A., B. and C.

D. Agglomeration of metal particles caused by thermal sintering of the solid surface

3050. With increase in K2/K1 in case of a unimolecular type elementary reactions as shown in the bellow figure, the fractional yield of R in mixed reactor (for a given conversion of A) ?
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A. Increases linearly

B. Increases

C. Decreases

D. Remain same