Explain why changes in both enthalpy and entropy determine the spontaneity of a process.

A reaction is said to be spontaneous if it occurs on its own without the aid of any external accelerating factor, and this is known as spontaneity of reaction, which is linked to the change in the reaction's Gibbs free energy.

The reaction's spontaneity is determined by the change in Gibbs free energy. The reaction is said to be spontaneous if the change in Gibbs free energy is negative, and non-spontaneous if the change is positive.

The Gibbs free energy is also influenced by the system's enthalpy and entropy. The Gibbs free energy of the reaction changes as the system's enthalpy and entropy fluctuate, which has an impact on the reaction's spontaneity.

Therefore, the changesin the enthalpy and entropy determines the spontaneity of the process.