Given:
- Xenon gas reacts with fluorine gas to form xenon hexafluoride. The chemical reaction can be represented as:
Xe + 3F2 → XeF6 - Overall energy change, ΔH, is -330 kJ/mol.
- The F-F bond energy is 158 kJ/mol.
To find:
The Xe-F bond energy.
Approach:
The overall energy change in the reaction is the difference between the energy required to break the bonds and the energy released when new bonds are formed.
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Calculate the total energy required to break the F-F bonds. There are 3 moles of F2, so 3 F-F bonds need to be broken.
Energy required to break 3 F-F bonds = 3 x F-F bond energy -
Let the Xe-F bond energy be x. Since there are 6 Xe-F bonds in xenon hexafluoride, the energy released when these bonds are formed is 6x.
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From the overall energy change, we can form the following equation:
Energy required to break bonds - Energy released when new bonds are formed = ΔH
3 x 158 kJ/mol - 6x = -330 kJ/mol
Solving for x, we get:
x = 134 kJ/mol