If the heat of combustion of C is -x , kJ,the | vedclass

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(A) The given thermochemical equations are:$(i)$ $C_{(s)} + O_{2(g)} 	o CO_{2(g)} \quad \Delta H_1 = -x \, kJ$(ii) $H_{2(g)} + \frac{1}{2}O_{2(g)}

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$(-x - 2y + z) \, kJ$

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(A) The given thermochemical equations are:$(i)$ $C_{(s)} + O_{2(g)} 	o CO_{2(g)} \quad \Delta H_1 = -x \, kJ$(ii) $H_{2(g)} + \frac{1}{2}O_{2(g)} 	o H_2O_{(l)} \quad \Delta H_2 = -y \, kJ$(iii) $CH_{4(g)} + 2O_{2(g)} 	o CO_{2(g)} + 2H_2O_{(l)} \quad \Delta H_3 = -z \, kJ$We need to find the heat of formation of $CH_4$ for the reaction:$C_{(s)} + 2H_{2(g)} 	o CH_{4(g)} \quad \Delta H_f = ?$Applying Hess's Law:$\Delta H_f = \Delta H_1 + 2 	imes \Delta H_2 - \Delta H_3$$\Delta H_f = (-x) + 2(-y) - (-z)$$\Delta H_f = (-x - 2y + z) \, kJ$

If the heat of combustion of $C$ is $-x \, kJ$,the heat of formation of $H_2O$ is $-y \, kJ$,and the heat of combustion of $CH_4$ is $-z \, kJ$,what is the heat of formation of $CH_4$?

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