Concept explainers
Use Table 8.3 to obtain AHO for the following thermochemical equations:
(a)
(b)
(c)
(a)
Interpretation:
The value of ΔH° for the given chemical equation needs to be calculated.
Concept introduction:
The change in standard enthalpy for a reaction,
Where, np and nr are the number of moles of the products and reactants
Answer to Problem 43QAP
ΔH° = +58.9 kJ
Explanation of Solution
The given chemical equation is as follows:
The amount of heat absorbed or evolved can be given in terms of the enthalpy change for the above reaction. Based on equation (1):
Putting the values from table 8.3:
(b)
Interpretation:
The value of ΔH° for the given chemical equation needs to be calculated.
Concept introduction:
The change in standard enthalpy for a reaction,
Where, np and nr are the number of moles of the products and reactants.
Answer to Problem 43QAP
ΔH° = +108.5 kJ
Explanation of Solution
The given chemical equation is:
The amount of heat absorbed or evolved can be given in terms of the enthalpy change for the above reaction. Based on equation (1), we have:
Putting the values from table 8.3 thus,
(c)
Interpretation:
The value of ΔH° for the given chemical equation needs to be calculated.
Concept introduction:
The change in standard enthalpy for a reaction,
Where, np and nr are the number of moles of the products and reactants.
Answer to Problem 43QAP
ΔH° = -179.9 kJ
Explanation of Solution
The given chemical equation is:
The amount of heat absorbed or evolved can be given in terms of the enthalpy change for the above reaction. Based on equation (1), we have:
Putting the values from table 8.3:
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Chapter 8 Solutions
Chemistry: Principles and Reactions
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