Concept explainers
Interpretation:
The reaction that can provide sufficient energy to do required work is to be identified.
Concept Introduction:
Standard Gibbs free energy of a reaction is used check whether the reaction is spontaneous or not. If the value of
Answer to Problem 8.15E
Correct answer:
The correct option is (b) and (d).
Explanation of Solution
Reason for correct answer:
(b)
The given chemical equation (b) is represented as,
From Table
The number of moles of electrons transferred in the above reaction is
The above equation is reversed and the value of
From Table
The number of moles of electrons transfer in the above reaction is
The relation between standard Gibbs free energy and standard electrical potential is represented as,
Where,
•
•
•
•
Substitute the values of the standard oxidation potential of
The value
Substitute the values of the standard reduction potential of
The value
The balanced overall electrochemical reaction is obtained when chemical equation (2) is multiplied by
Therefore, the value
The maximum amount of work that can be done by the given chemical reaction (b) is
(d)
The given chemical equation (d) is represented as,
From Table
The above equation is reversed and the value of
The number of moles of electrons transfer in the above reaction is
From Table
The number of moles of electrons transfer in the above reaction is
Substitute the values of the standard oxidation potential of
The value
Substitute the values of the standard reduction potential of
The value
The balanced overall electrochemical reaction is obtained when chemical equation (5) is multiplied by
Therefore, the value
The required work done is
Therefore, the given reaction (b) and (d) can provide enough energy to perform the process.
The correct options are (b) and (d).
Reason for incorrect options:
(a)
The given chemical equation (a) is represented as,
From Table
The number of moles of electrons transfer in the above reaction is
From Table
The number of moles of electrons transfer in the above reaction is
The above equation is reversed and the value of
Substitute the values of the standard reduction potential of
The value
The standard electrical potential of the reaction (7) is
The balanced overall electrochemical reaction is obtained when chemical equation (6) is added in chemical equation (7). The formation of overall balanced chemical equation is represented as,
Therefore, the value
(c)
The given chemical equation (c) is represented as,
From Table
The above equation is reversed and the value of
The chemical equation (7) is reversed and the value of
The number of moles of electrons transfer in the above reaction is
Substitute the values of the standard oxidation potential of
The value
Substitute the values of the standard reduction potential of
The value
The balanced overall electrochemical reaction is obtained when chemical equation (8) is added in chemical equation (9). The formation of overall balanced chemical equation is represented as,
The value
The energy produce by the reaction (a) and (b) is less than the required energy.
Therefore, the option (a) and (c) are incorrect.
The reaction (b) and reaction (d) provides sufficient amount of energy to do required work. Therefore, the option (b) and (d) are correct.
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Chapter 8 Solutions
Physical Chemistry
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