The standard enthalpy of formation `(Delta_(f)H^(@))` at `298K ` for methane `(CH_(4(g)))` is `-74.8kJ mol^(-1)`. The additional information required to determine the average energy for `C-H` bond formation would be `:`

Options

A. Latent heat of vapourization of methane
B. The first four ionization energies of carbon and electron gain ethalpy of hydrogen
C. The dissociation energy of hydrogen molecule `H_(2)`
D. The dissociation energy of `H_(2)` and enthalpy of sublimation of carbon

Answer

D

Explanation

`C_((s))+2H_(2(g))rarr CH_(4(g)), Delta H_(f)(CH_(4))=-74.8 kJ mol^(-1)`
`C_((s))rarr C_((g)) , Delta H`
`Delta H=(B.E.)_(R )-(B.E.)_(P)`
`Delta H=[Delta H_(C(s)rarr C(g))+2xx(B.E.)_(H-H)]-4xx(B.E.)_(C-H)`