Chemical Reaction Engineering — Part 2 MCQs with Explanations

Film is the correct answer to “If a solid-gas non-catalytic reaction occurs at very high temperature, the rate controlling step is the __________ diffusion.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

9210°K is the correct answer to “The rate constant of a chemical reaction increases by 100 times when the temperature is increased from 400 °K to 500 °K. Assuming transition state theory is valid, the value of E/R is”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

A + A ⇋ AA; AA + B → A2B is the correct answer to “Find a mechanism that is consistent with the rate equation and reaction given below: 2A + B → A 2 B, (-r A ) = k.C A .C B”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

K3 = K₁.K₂ is the correct answer to “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:”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Activation is the correct answer to “The catalytic activity of enzymes is due to their capacity to lower the __________ energy.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Bubbling bed is the correct answer to “For a fluidised bed reactor, the most suitable/relevant model is a __________ model.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

None of these is the correct answer to “Which of the following is not a unit of reaction rate”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Proportional to is the correct answer to “Overall rate of reaction in a heterogenous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of catalyst, if it does not entail a chain mechanism.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Reversible endothermic is the correct answer to “Conversion increases with increase in temperature in case of a an __________ reaction.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

24 is the correct answer to “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.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

$$\frac{1}{2}$$ is the correct answer to “What is the value of 'n' if the reaction rate of the chemical reaction A → B, is proportional to C A n and it is found that the reaction rate triples, when the concentration of 'A' is increased 9 times”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Non-elementary is the correct answer to “There is no correspondence between stoichiometry and the rate equation in case of a/an __________ reaction.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Increase of reaction time is the correct answer to “For a zero order reaction, the concentration of product increases with the”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

75 is the correct answer to “The conversion for a first order liquid phase reaction. A → B in a CSTR is 50%. If another CSTR of the same volume is connected in series, then the % conversion at the exit of the second reactor will be”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Temperature is the correct answer to “The rate constant of a first order reaction depends on the”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Mixed reactor is always larger than the plug-flow reactor is the correct answer to “For all positive reaction orders for a particular duty,”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

$${\text{t}} \propto \frac{1}{{{{\text{a}}^{{\text{n}} - 1}}}}$$ is the correct answer to “If n = overall order of a chemical reaction. a = initial concentration of reactant. t = time required to complete a definite fraction of the reaction. Then pick out the correct relationship.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Slow reactions in catalyst of small pore diameter is the correct answer to “In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

$$\frac{{{{\text{F}}_{{{\text{A}}_{\text{0}}}}}}}{{\text{V}}} \cdot {{\text{X}}_{\text{A}}}$$ is the correct answer to “For a mixed flow reactor operating at steady state, the rate of reaction is given by”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

And backward reaction equally is the correct answer to “The catalyst in a second order reversible reaction increases the rate of the forward reaction”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Initiated by is the correct answer to “A photochemical reaction is __________ light.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Temperature of the system is the correct answer to “The rate constant of a reaction is a function of the”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Increase is the correct answer to “With increase in the space time of an irreversible isothermal reaction being carried out in a P.F. reactor, the conversion will”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Active mass is the correct answer to “The rate at which a chemical substance reacts is proportional to its”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

More when they are connected in series is the correct answer to “A first order reaction requires two equal sized CSTR. The conversion is”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

(i) decreases (ii) increases is the correct answer to “In the converter of the contact process for the manufacture of H 2 SO 4 the equilibrium conversion of SO 2 ____(i)____ with increase in temperature and ___(ii)___ with increase in the mole ratio of SO 2 to air.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

0 is the correct answer to “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”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

1 is the correct answer to “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”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

rA = -rB is the correct answer to “For the reaction, A + B → 2B + C,”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Be more in PFR than in CSTR is the correct answer to “An irreversible first order reaction is being carried out in a CSTR and PFR of same volume. The liquid flow rates are same. The relative conversion will”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Proteinous in nature is the correct answer to “Organic catalysts differ from the inorganic catalyst in the sense that the former is”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

∞ is the correct answer to “For an ideal plug flow reactor, the value of Peclet number is”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

3 is the correct answer to “If the time required for half change is inversely proportional to the square of initial concentration and the velocity depends on the units in which the concentration term is expressed, then the order of reaction is”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

1/(time)(concentration)n - 1 is the correct answer to “If 'n' is the order of reaction, then unit of rate constant is”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

All of the above is the correct answer to “A stirred tank reactor compared to tubular-flow reactor provides”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

There is no dynamic equilibrium between successive layer is the correct answer to “Brunaur, Emmet and Teller (BET) equation is used to determine the specific surface area of a porous particle but not the pore volume & the porosity of the catalyst bed. Which of the following postulates is not used to derive BET equation”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Five reactor volumes of feed (at specified conditions) are being fed into the reactor per hour is the correct answer to “A space velocity of 5 hr -1 means that”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Decrease is the correct answer to “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.”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Both A and B is the correct answer to “For multiple reactions, the flow pattern within the vessel affects the”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.

Decreases is the correct answer to “If helium is introduced in a reactor containing O 2 , SO 2 and SO 3 at equilibrium, so that total pressure increases while volume and temperature remains constant. In this case the dissociation of SO 3 (as per Le Chatlier principle)”. This question is standard in competitive examination syllabi for Chemical Reaction Engineering.