Questions and answers for exam Preparation

MCQs

Total Questions : 2307 | Page 231 of 231 pages

Question 2301. Pick out the wrong statement?

In a first order reaction, A → products; the reaction becomes slower as it proceeds, because the concentration of A decreases and the rate is propor
Transition state theory approaches the problem of calculating reaction rates by concentrating on the idea of activated complexes
According to the penetration theory, the mass transfer co-efficient decreases, if the exposure time of an eddy to the solute decreases
If the rate of an irreversible reaction, A + B → 2C is k.CA.CB, then the reaction is always elementary

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Answer: Option C. -> According to the penetration theory, the mass transfer co-efficient decreases, if the exposure time of an eddy to the solute decreases
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2302. Pick out the wrong statement ?

Autocatalytic reactions are exemplified by microbial fermentation reactions
The slowest step has the greatest influence on the overall reaction rate in case of an irreversible series reaction
The fractional conversion at any time is same for both the constant as well as the variable volume system in case of an irreversible unimolecular type
Hydrolysis of ester in presence of alkali or acid is a zero order reaction

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Answer: Option D. -> Hydrolysis of ester in presence of alkali or acid is a zero order reaction
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2303. Pick out the correct statement ?

A catalyst does not change AH of the reaction
A catalyst changes the equilibrium point
Law of mass action was suggested by Le-Chatelier
The difference between the energy of reactants and that of the products is the activation energy

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Answer: Option A. -> A catalyst does not change AH of the reaction
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2304. Pick out the correct statement ?

A chemical reaction accompanied by absorption of heat is called an exothermic reaction
A chemical reaction accompanied by evolution of heat is called an endothermic reaction
The rate constant for a first order reaction does not change on changing the concentration units
Chemical equilibrium state is dynamic in nature

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Answer: Option C. -> The rate constant for a first order reaction does not change on changing the concentration units
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2305. Pick out the wrong statement ?

For the same conversion, the holding time required in a batch reactor, is always equal to the space time required in a PFR
Two mixed reactors of unequal size are available for producing a specified product, formed by a homogenous second order reaction. To achieve maximum p
Arrhenius equation describing the effect of temperature on rate constant is given by, K = A.e-Ea/RT
The mechanism for the decomposition of CH3CHO into CH4 and CO in presence of I2 is: CH3CHO + I2 → CH3I + HI + CO; slow CH3I + HI → CH4 + I2; fast

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Answer: Option D. -> The mechanism for the decomposition of CH3CHO into CH4 and CO in presence of I2 is: CH3CHO + I2 → CH3I + HI + CO; slow CH3I + HI → CH4 + I2; fast
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2306. Pick out the correct statement ?

A catalyst speeds up the forward reaction but slows shown the reverse reaction
Addition of catalyst changes the equilibrium constant
Pressure changes do not change the equilibrium concentrations
The composition of equilibrium is changed by catalyst

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Answer: Option C. -> Pressure changes do not change the equilibrium concentrations
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2307. Pick out the wrong statement ?

For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity
For an ideal mixed reactor at steady state, the exit stream has the same composition as fluid within the reactor and the space time is equivalent to h
Plug flow reactor (PFR) is always smaller than mixed reactor for all positive reaction orders for a particular duty
Reaction rate does not decrease appreciably as the reaction proceeds in case of an autocatalytic reaction

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Answer: Option A. -> For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!