Question

Which of the following would describe a spontaneous process? (Select all that apply.) ΔGreaction < 0 ΔSuniverse < 0 ΔSuniverse > 0 ΔHreaction > 0 ΔHreaction < 0 ΔGreaction > 0

Answer 1

Answer:

ΔGreaction < 0

ΔSuniverse > 0

ΔHreaction < 0

Explanation:

A spontaneous process is one which can proceed without additional input of energy releasing free energy in the process and then moves to a lower more stable thermodynamical state.

For an isolated system, a spontaneous process proceeds with an increase in entropy.

The conditions for a spontaneous process at constant temperature and pressure, can be determined using the change in Gibbs free energy, which is given by: ∆G = ∆H - T∆S

Where ∆G is change in free energy; ∆H is change in enthalpy or Heat content; ∆S is change in entropy, T is temperature.

For a process to be spontaneous, the following conditions are necessary:

1. ∆G < 0; must be negative

2. ∆S > 0; there must be an increase in entropy

3. ∆H < 0; enthalpy change must be negative such that heat is lost to the surroundings

The above conditions ensures that ∆G is negative and the process is spontaneous.