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Heat of Formation

Methylene chloride can be prepared from the reaction of methane and chlorine, by the following equation:
CH4(g) + Cl2(g) ---> CH2Cl2(g) + HCl(g)
Calculate the standard heat of formation in kilojoules for the reaction using the following measured heats of formation.
HCl(g) + CH3Cl(g) --> CH4(g) + Cl2(g) Delta H = +98.3 kJ
CH3Cl(g)+ Cl2(g) --> CH2Cl2(g) + HCl(g) Delta H = -104kJ

Solution Preview

First balance the equation:
CH4(g) + Cl2(g) ---> CH2Cl2(g) + HCl(g)
CH4(g) + 2Cl2(g) ---> CH2Cl2(g) + 2HCl(g)
Now rewrite
HCl(g) + CH3Cl(g) --> CH4(g) + ...

Solution Summary

The solution provides a detailed calculation of the heat of formation (which includes balancing equations).