Question

Calculate the average molar bond enthalpy of the carbon-hydrogen bond in a ch4 molecule.

Answer 1

The average molar bond enthalpy of the carbon-hydrogen bond in a CH4 molecule is 416 KJ/mol. (+716.7 + (4 x 218) - (- 74.6) ) / 4 = + 1663.3 / 4 = 416

Answer 2

Answer:

415.825 kJ/mol.

Explanation:

Average enthalpy = $\Delta H_f(CH_4)-4\Delta H_f(H)-\Delta H_f(C)$

Now, $\Delta H_f(CH_4)=-74.6 kJ/mol$

         $\Delta H_f(H)=218 kJ/mol$

         $\Delta H_f(C)=716.7 kJ/mol$

( SOURCE INTERNET)

Putting all these values above.

We get,

Average enthalpy=-1663.3 kJ.

Therefore, averagemolar bond enthalpy= $\dfrac{1663.3 }{4}=415.825\ kJ/mol.$

Hence, this is the required solution.