If `DeltaH_(f)(X)`, `DeltaH_(f)(Y)`, `DeltaH_(f)(R )` and `DeltaH_(f)(S)` denote the enthalpies of formation of `X`, `Y`, `R` and `S` respectively, the enthalpy of the reaction `X+YtoR+S` is given by

Options

A. `Delta_f H (X) + Delta_ f H (Y)`
B. `Delta_f H (R ) + Delta _f H (S)`
C. `Delta_f H (X) + Delta_(f)H ( Y )- Delta_f H ( R) - Delta_f H (S) `
D. `Delta_f H( S) + Delta_f H( R) - Delta_f H (X) - Delta_f H (Y)`

Answer

B

Explanation

`Delta_r H = Sigma Delta_f H^@` (Products) `-Sigma Delta_f H^@` (Reactants)