Using data from Appendix 2, calculate
Interpretation:
The standard entropy change of the reaction and the entropy change of surroundings, for the given reaction and the spontaneity of the given reaction are to be determined.
Concept introduction:
The standard enthalpy change of the reaction,
Here,
Answer to Problem 23QP
Solution:
The standard entropy change of the reaction is
The entropy change of the surrounding is
The reaction isspontaneous.
The standard entropy change of the reaction is
The entropy change of the surrounding is
The reaction is not spontaneous.
The standard entropy change of the reaction is
The entropy change of the surrounding is
The reaction is not spontaneous.
The standard entropy change of the reaction is
The entropy change of the surrounding is
The reaction is spontaneous.
Explanation of Solution
a)
Calculate entropy change of the universe for the given reaction.
The entropy change of the universe for this reaction is calculated using the following expression:
Here,
The enthalpy change of the system
The standard enthalpy change of the reaction
Here,
From appendix 2, the standard enthalpy change of formation for the substances are as follows:
Substitute the standard enthalpy change of the formation value of the substance in the above expression,
The standard entropy change for this reaction is calculated using the following expression:
Substitute the value of
Therefore, the entropy change of the surrounding is
Calculate the standard entropy change of the given reaction.
The standard entropy change for this reaction is calculated using the following expression:
Here,
and
From appendix 2, the standard entropy values for the substances are as follows:
Substitute the standard entropy value of the substance in the above expression,
Therefore, the standard entropy change for this reaction is
Calculate the entropy change of the universe.
The entropy change of the universe is calculate using the following expression:
Substitute the value of
Therefore, entropy change of the universe for this reaction is
For the spontaneity of reaction, the value of
The entropy change of the universe for this reaction is positive.
Therefore, the reaction isspontaneous.
b)
Calculate entropy change of the universe for the given reaction.
The entropy change of the universe for this reaction is calculated using the following expression:
Here,
The enthalpy change of the system
The standard enthalpy change of the reaction
Here,
From appendix 2, the standard enthalpy change of the formation for the substances are as follows:
Substitute the standard enthalpy change of the formation value of the substances in the above expression.
The standard entropy change for this reaction is calculated using the following expression:
Substitute the value of
Therefore, the entropy change of the surrounding is
Calculate the standard entropy change of the given reaction.
The standard entropy change for this reaction is calculated using the following expression:
Here,
and
From appendix 2, the standard entropy value of the substances are as follows:
Substitute the standard entropy value of the substance in the above expression,
Therefore, the standard entropy change for this reaction is
Calculate the entropy change of the universe.
The entropy change of the universe is calculate using the following expression:
Substitute the value of
Therefore, entropy change of the universe for this reaction is
For the spontaneity of reaction, the value of
The entropy change of the universe for this reaction is negative.
Therefore, the reaction is not spontaneous.
c)
Calculate entropy change of the universe for the given reaction.
The entropy change of the universe for this reaction is calculated using the following expression:
Here,
The enthalpy change of the system
The standard enthalpy change of the reaction
Here,
From table 8.6, bond enthalpy of the elements are as follows:
Substitute the standard enthalpy change of the formation value of the substance in the above expression,
The standard entropy change for this reaction is calculated using the following expression:
Substitute the value of
Therefore, the entropy change of the surrounding is
Calculate the standard entropy change of the given reaction.
The standard entropy change for this reaction is calculated using the following expression:
Here,
and
From the appendix 2 the standard entropy value of the substances are as follows:
Substitute the standard entropy value of the substance in the above expression,
Therefore, the standard entropy change for this reaction is
Calculate the entropy change of the universe.
The entropy change of the universe is calculate using the following expression:
Substitute the value of
Therefore, entropy change of the universe for this reaction is
For the spontaneity of reaction, the value of
The entropy change of the universe for this reaction is negative.
Therefore, the reaction is not spontaneous.
d)
Calculate entropy change of the universe for the given reaction.
The entropy change of the universe for this reaction is calculated using the following expression:
Here,
The enthalpy change of the system
The standard enthalpy changes of the reaction
Here,
From appendix 2, the standard enthalpy change of the formation for the substances are as follows:
Substitute the standard enthalpy change of the formation value of the substances in the above expression,
The standard entropy change for this reaction is calculated using the following expression:
Substitute the value of
Therefore, the entropy change of the surrounding is
Calculate the standard entropy change of the given reaction.
The standard entropy change for this reaction is calculated using the following expression:
Here,
and
From appendix 2, the standard entropy value of the substances are as follows:
Substitute the standard entropy value of the substance in the above expression,
Therefore, the standard entropy change for this reaction is
Calculate the entropy change of the universe.
The entropy change of the universe is calculate using the following expression:
Substitute the value of
Therefore, entropy change of the universe for this reaction is
For the spontaneity of reaction, the value of
The entropy change of the universe for this reaction is positive.
Therefore, the reaction is spontaneous.
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Chapter 18 Solutions
CHEMISTRY LOOSELEAF TEXT W/CONNECT >IP
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