Question

The molar enthalpies of combustion of `C_(2)H_(2)(g), C("graphite")` and `H_(2)(g)`are `-1300,-394`, and `-286 kJ mol^(-1)`, respectively. The standard enthalpy of formation of `C_(2)H_(2)(g)` is
A. `-226 kJ mol^(-1)`
B. `-626 kJ mol^(-1)`
C. `226 kJ mol^(-1)`
D. `626 kJ mol^(-1)`

Answer 1

`Delta_(f)H^(Theta) = (Delta_(f)H_(P)^(Theta) -Delta_(f)H_(R)^(Theta))`