Which of the reaction defines `Delta_(f)H^(@)` ?

Options

A. `C_((diamon d))+O_(2) rarr CO_(2(g))`
B. `1/2H_(2(g))+(1)/(2)F_(2(g))rarrHF_((g))`
C. `N_(2(g))+3H_(2(g))rarr 2NH_(3(g))`
D. `CO_((g))+(1)/(2)O_(2(g))rarr CO_(2(g))`

Answer

B

Explanation

No doubt `(a)` and `(b)` both represents heat of formations but standard heat of formation `Delta_(f)H^(@)` for `CO_(2)` will be from `C_(graph ite )+O_(2) rarr CO_(2)` as graphite is most stable form of carbon.