Use standard enthalpies of formation to calculate the value of `Delta_(r )H^(Θ)` for the reaction
`2H_(2)S(g) + 3O_(2)(g) rarr 2H_(2)O(l) + 2SO_(2)(g)`

Explanation

`DeltaH^(Θ)=Sigmav_(p) Delta_(f)H^(Θ)("products")- SigmaV_(f) Delta_(f)H^(Θ) ("reactants")`
`=-[2Delta_(f)H^(Θ)(H_(2)S, g)+3Delta_(f)H^(Θ)(O_(2),g)`
`=-2xx285.8 kJ mol^(-1)-2 xx296.9 kJ mol^(-1)+2xx20.1 kJ mol^(-1)+3xx0 [:' Delta_(f)H^(Θ)(O_(2), g)=0]`
`=-1125.2 kJ mol^(-1)`