Sulphur exists is more than one solid form. The stable form at room temperature is rhombic sulphur. But above room temperature the following reaction occurs.
`S ("rhomic") rarrS("monoclinic")`
If `DeltaH^(Theta) = 276.144J at 298 K` and `1atm` and `DeltaG^(Theta) = 75.312J`
a. Calculate `DeltaS^(Theta)` at `298K`.
b. Assume that `DeltaH^(Theta)` and `DeltaS^(Theta)` do not vary significantly with temperature, calculate `T_(eq)`, the temperature at which rhombic and monoclinic sulphur exist in equilibrium with each other.

Explanation

(a) Since `DeltaG = DeltaH - TDeltaS`
`DeltaS = (DeltaH - DeltaG)/T`
`=(276.144 - 75.312)/298`
`=0.674 JK^(-1)`
(b) Under equilibrium condition, `DeltaG=0`
`DeltaH = T_(eq)DeltaS=0`
`T_(eq) = (DeltaH)/(Deltas) = (276.144)/0.674`
= 409.7 K