Using data from Appendix 2, calculate
Interpretation:
The standard entropy change, the entropy change of the surroundingsand the spontaneity of the given reactions are to be determined.
Concept introduction:
The standard enthalpy change of a reaction
Here,
Answer to Problem 22QP
Solution:
The standard entropy change of the reaction is
The entropy change of the surroundings is
Reaction is not spontaneous.
The standard entropy change of the reaction is
The entropy change of the surroundings is
Reaction is spontaneous
The standard entropy change of the reaction is
The entropy change of the surroundings is
Reaction is spontaneous.
The standard entropy change of the reaction is
The entropy change of the surroundings is
Reaction is not spontaneous.
Explanation of Solution
a)
The entropy change of the universe for this reaction is calculated by using the expression as follows:
Here,
The enthalpy change of the system
The standard enthalpy change of the reaction
Here,
From appendix 2, the standard enthalpy changesfor the formation of the substances are as follows:
Substitute the value of the standard enthalpy change of the formation of the substance in the above expression,
The standard entropy change for this reaction is calculated by using the expression as follows:
Substitute the values of
Therefore, the entropy change of the surroundings is
Calculate thestandard entropy change of the given reaction.
The standard entropy change for this reaction is calculated by using the expression as follows:
Here,
and
From appendix 2, the standard entropy values 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 calculated by using the expression as follows:
Substitute the values of
Therefore, the entropy change of the universe for this reaction is
For the spontaneity of the reaction, the value of
The entropy change of the universe for this reaction is negative.
Therefore, the reaction is not spontaneous.
b)
Calculate the entropy change of the universe for the given reaction.
The entropy change of the universe for this reaction is calculated by using the expression as follows:
Here,
The enthalpy change of the system
The standard enthalpy change of the reaction
Here,
From appendix 2, the standard enthalpy changesfor the formation of the substances are as follows:
Substitute thevalue of the standard enthalpy change for the formation of the substance in the above expression,
The standard entropy change for this reaction is calculated by using the expression as follows:
Substitute the values of
Therefore, the entropy change of the surroundings is
Calculate thestandard entropy change of the given reaction.
The standard entropy change for this reaction is calculated by using the expression as follows:
Here,
and
From appendix 2, the standard entropy values of the substance 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 calculated by using the expression as follows:
Substitute the value of
Therefore, the entropy change of the universe for this reaction is
For the spontaneity of the reaction, the value of
The entropy change of the universe for this reaction is positive.
Therefore, the reaction is spontaneous.
c)
Calculate the entropy change of the universe for the given reaction.
The entropy change of the universe for this reaction is calculated by using the expression as follows:
Here,
The enthalpy change of the system
The standard enthalpy change of the reaction
Here,
From appendix 2, the standard enthalpy changesfor the formation of the substances are as follows:
Substitute thevalue of the standard enthalpy change for the formation of the substance in the above expression.
The standard entropy change for this reaction is calculated by using the expression as follows:
Substitute the values of
Therefore, the entropy change of the surroundings is
Calculate thestandard entropy change of the given reaction.
The standard entropy change for this reaction is calculated by using the expression as follows:
Here,
and
From appendix 2, the standard entropy values of the substances are as follows:
Substitute the value of the standard entropy 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 calculated by using the expression as follows:
Substitute the values of
Therefore, the entropy change of the universe for this reaction is
For a spontaneous reaction, the value of
The entropy change of the universe for this reaction is positive.
Therefore, the reaction is spontaneous.
d)
Calculate the entropy change of the universe for the given reaction.
The entropy change of the universe for this reaction is calculated by using the expression as follows:
Here,
The enthalpy change of the system
The standard enthalpy change of the reaction
Here,
From appendix 2, the standard enthalpy change for the formation of the substance are as follows:
Substitute thevalue of the standard enthalpy change for the formation of the substance in the above expression,
The standard entropy change for this reaction is calculated by using the expression as follows:
Substitute the values of
Therefore, the entropy change of the surroundings is
Calculate thestandard entropy change of the given reaction.
The standard entropy change for this reaction is calculated by using the expression as follows:
Here,
and
From appendix 2, the standard entropy values of the substances are as follows:
Substitute the value of the standard entropy 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 calculated by using the expression as follows:
Substitute the values of
Therefore, the entropy change of the universe for this reaction is
For a spontaneous reaction, the value of
The entropy change of the universe for this reaction is negative.
Therefore, the reaction is not spontaneous.
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Chapter 18 Solutions
ALEKS 360 CHEM ACCESS CARD
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