Gibbs-Helmoholtz equation relates the free energy change to the enthalpy and entropy changes of the process as
`(DeltaG)_(PT) = DeltaH - T DeltaS`
The magnitude of `DeltaH` does not change much with the change in temperature but the enrgy factor `T DeltaS` changes appreciably. Thus, spontaneity of a process depends very much on temperature.
When `CaCO_(3)` is heated to a high temperature, it undergoes decomposition into `CaO` and `CO_(2)` whereas it is quite stable at room temperature. The most likely explanation of its is

Options

A. The enthalpy of reaction `(DeltaH)` overweighs the term `T DeltaS` at high temperature.
B. The term `T DeltaS` overweights the enthalpy of reaction at high temperature
C. At high temperature, both enthalpy of reaction and entropy change becomes negative.
D. None of these.

Explanation

`DeltaG = DeltaH - T DeltaS`, at high temperature `T DeltaS` factor dominates of `DeltaH` and hence `DeltaG` becomes negative and reaction occurs spontaneously.