Spontaneity
Spontaneity: Overview
This topic covers concepts, such as, Spontaneity, Spontaneous Reactions, Non-spontaneous Reactions, Entropy, Factors Affecting Entropy & Spontaneity in Terms of Entropy Change etc.
Important Questions on Spontaneity
For vaporization of water at 1 atmospheric pressure, the values of respectively. The temperature when Gibbs energy change for this transformation will be zero, is:

The values of for the reaction, respectively. This reaction will be spontaneous at

Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is:


of an ideal gas at temperature is expanded reversibly from to . Find the entropy change.

The enthalpy of vaporization of water at is . Its entropy of vaporization would be


mole of an ideal gas at expands reversibly from litre to litre. The entropy change is:

List I (Equations) | List II (Type of Processes) |
(A) | (p) Non-spontaneous |
(B) | (q) Equilibrium |
(C) | (r) Spontaneous and endothermic |
(D) | (s) Spontaneous |
Matching Type Question

The standard entropy change accompanying the cell reaction will be

Enthalpy change for the process,
is ,
the entropy change of mole of ice at its melting point will be

Calculate hence show whether the following reaction is spontaneous at

For which of the following reactions is negative?

Which of the following processes is nonspontaneous?

For the conversion of liquid to solid below the melting point of solid


Which member of the pair has larger entropy and why? or .

Which member of the pair has larger entropy and why? or .

Which member of the pair has larger entropy and why? or .

Which member of the pair has larger entropy and why? or .
