Question

Why gibbs eneregy is negative for spontaneous recovery?

Answer 1

The second law of thermodynamics says that the entropy of the universe always increases for a spontaneous process:

\Delta \text {S}_{\text{universe}}=\Delta \text {S}_{\text{system}} + \Delta \text {S}_{\text{surroundings}} > 0

ΔS

universe

=ΔS

system

+ΔS

surroundings

>0

At constant temperature and pressure, the change in Gibbs free energy is defined as

\Delta \text G = \Delta \text H - \text{T}\Delta \text S

ΔG=ΔH−TΔS.

When

\Delta \text G

ΔG is negative, a process will proceed spontaneously and is referred to as exergonic.

The spontaneity of a process can depend on the temperature.

Spontaneous processes

In chemistry, a spontaneous processes is one that occurs without the addition of external energy. A spontaneous process may take place quickly or slowly, because spontaneity is not related to kinetics or reaction rate. A classic example is the process of carbon in the form of a diamond turning into graphite, which can be written as the following reaction:

\text C(s, \text {diamond}) \rightarrow \text C(s, \text{graphite})

C(s,diamond)→C(s,graphite)