The heat of transition of `S_(alpha)` into `S_(beta)` is +2.5 kJ. The heat of combustion of monoclinic sulphur is `- 300 kJ mol^(-1)`. Calculate heat of combustion of rhombic sulphur`(S_(alpha))`.

Explanation

`S_(alpha) to S_(beta), DeltaH = +2.5 kJ ` and
`S_(beta) + O_(2(g)) to SO_(2(g)) , DeltaH = -300 KJ`
Adding these two, the heat of combustion of `S alpha` is obtained. `S_(alpha) + O_(2(g)) to SO_(2(g)) , DeltaH = -297.5 kJ`.