Engineering Questions with Answers - Multiple Choice Questions
Unit Processes MCQ’s – Thermodynamics and Kinetics
1 - Question
What is an equilibrium state?
a) Extent of reaction
b) Optimum condition
c) Least value product
d) All of the mentioned
View Answer
Explanation: The extent to which a chemical reaction may proceed under a given set of conditions is given by the equilibrium state
2 - Question
What is the driving force in a reaction?
a) Energy given
b) Energy released
c) Free energy
d) None of the mentioned
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Explanation: The driving force of the reaction is the change in free energy, which is related to the equilibrium constant (K).
3 - Question
What should be the free energy so that reaction is spontaneous?
a) Positive
b) Negative
c) Neutral
d) None of the mentioned
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Explanation: If the free energy change is negative the reaction is spontaneous and becomes more favourable with increasing (-dF); on the other hand if the free energy change is positive and greater than 10 kg-cal per mole the reaction is not suitable for practical application.
4 - Question
What does hydrolysis of Alkyl Chlorides produce?
a) Unsaturated compound
b) Alcohol
c) Aldehyde
d) None of the mentioned
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Explanation: Hydrolysis of Alkyl Chlorides produces alcohol and hydrochloric acid as by-product.
5 - Question
What type of reaction is Hydrolysis of Alkyl Chlorides?
a) Endothermic
b) Exothermic
c) Neutral
d) None of the mentioned
View Answer
Explanation: Hydrolysis of Alkyl Chlorides, here an estimation of the change in heat content (enthalpy) from bond energies shows this hydrolysis to be endothermic.
6 - Question
Hydrolysis of Ethyl Acetate is an irreversible reaction.
a) True
b) False
View Answer
Explanation: Hydrolysis of Ethyl Acetate is a reversible esterification reaction.
7 - Question
What is the heat of reaction for hydrolysis of Ethyl Acetate?
a) Greater than zero
b) Less than zero
c) Zero
d) None of the mentioned
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Explanation: In hydrolysis of ethyl acetate, the equilibrium position was shown to be independent of the temperature. A calculation of the heat of reaction by the method of bond energies gives a value of zero, since the bonds broken are of the same type as the bonds formed.
8 - Question
Which type of reaction is inversion of Sucrose?
a) Reversible
b) Irreversible
c) All of the mentioned
d) None of the mentioned
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Explanation: In inversion of Sucrose, many hydrolytic reactions, including the decomposition of esters, are reversible; but others such as sucrose inversion and protein hydrolysis, though not necessarily complete, have not been reversed.
9 - Question
The speed of reaction is no important in attaining equilibrium.
a) True
b) False
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Explanation: In commercial processes, whether a reaction goes fast or slow is extremely important, and thus the rate at which a chemical reaction approaches equilibrium is significant.
10 - Question
What is meant by ‘Z’ in Arrhenius equation?
a) Energy of activation
b) Gas constant
c) Probability factor
d) Frequency of collision
View Answer
Explanation: In Arrhenius equation, E is the energy of activation, R the gas constant, Z the frequency of collision at unit concentration of reactants, and P a probability factor.
11 - Question
What is ‘transition-state theory’ related to?
a) Free energy
b) Activated complex
c) Transition state
d) All of the mentioned
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Explanation: The transition-state theory, places emphasis on the free energy of activation and is concerned with the thermodynamic probability of attaining an “activated complex,” or transition state.
12 - Question
Hydrolysis of ester is catalysed by what?
a) Hydroxyl ion
b) Nitrite ion
c) Halogen
d) All of the mentioned
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Explanation: Extensive study of the hydrolysis of esters has shown that the reaction is reversible and is catalyzed by both oxonium (H3O+) and hydroxyl (OH-) ions.
13 - Question
Hydrolysis of alkyl halide is possible in which type of mechanism?
a) Unimolecular
b) Bimolecular
c) Both unimolecular and bimolecular
d) None the mentioned
View Answer
Explanation: In alkyl halides, there are two possible mechanisms3 for the reaction, one is unimolecular and other is bimolecular.