The standard enthalpy of formation (Delta_fH^ | vedclass

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(D) The formation reaction of methane is: $C_{(s)} + 2H_{2(g)} \rightarrow CH_{4(g)}$.To calculate the average $C-H$ bond energy,we need to consider t

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Dissociation energy of $H_2$ and enthalpy of sublimation of carbon

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(D) The formation reaction of methane is: $C_{(s)} + 2H_{2(g)} ightarrow CH_{4(g)}$.To calculate the average $C-H$ bond energy,we need to consider the atomization of the reactants into gaseous atoms: $C_{(s)} ightarrow C_{(g)}$ (enthalpy of sublimation) and $2H_{2(g)} ightarrow 4H_{(g)}$ (dissociation energy of $H_2$).Then,the enthalpy of formation is related to the bond energies by the equation: $\Delta_fH^o = [\Delta_{sub}H(C) + 2 	imes BE(H-H)] - [4 	imes BE(C-H)]$.Thus,we need the enthalpy of sublimation of carbon and the dissociation energy of $H_2$.

The standard enthalpy of formation $(\Delta_fH^o)$ of methane $(CH_{4(g)})$ at $298 \, K$ is $-74.8 \, kJ \, mol^{-1}$. What additional information is required to calculate the average bond energy of the $C-H$ bond?

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