Question

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

Answer 1

415.825 kJ/mol.

Step-by-step 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=
`(1663.3 )/(4)=415.825\ kJ/mol.`

Hence, this is the required solution.

Answer 2

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