Question

Part A

For a single substance at atmosphericpressure, classify the following as describing a spontaneousprocess, a nonspontaneous process, or an equilibrium system.

1. Solid melting above its melting point
2.liquid freezing below its freezing point
3. gas condensing above its condensation point
4. liquid vaporizing below its boiling point
5. solid melting below its melting point
6. solid and liquid together at the melting point with no netfreezing or melting
7. gas condensing below its condensation point
8. liquid and gas together at the boiling point with no netcondensation or vaporization
9. liquid freezing above its freezing point
10. liquid vaporizing above its boiling point

Answer 1

Concepts and reason

Chemical or physical processes can be termed as spontaneous, non-spontaneous or at equilibrium from the thermodynamic point of view.

Classify the given processes as spontaneous, non-spontaneous or at equilibrium.

Fundamentals

A spontaneous process is the one which proceeds with a lowering of Gibbs free energy.

The final product of the process has less energy than the initial reacting species or reactant. That is, the process proceeds with release of energy. $\Delta {\rm{G < 0}}$.

A non-spontaneous process is one which proceeds with increase in Gibbs free energy. Absorption of energy takes place in a non-spontaneous process. $\Delta {\rm{G > 0}}$.

A process in equilibrium is an intermediate between the spontaneous and non-spontaneous. The free energy change remains zero here. $\Delta {\rm{G}} = {\rm{0}}$.

Changing the thermodynamics factors such as entropy, temperature and pressure conditions spontaneous, non-spontaneous and equilibrium process can be interconverted.

Consider the given statements regarding physical or chemical processes:

1.Solid melting above its melting point.

2.Liquid freezing below its freezing point.

3.Gas condensing above its condensation point.

4.Liquid vaporising below its boiling point.

5.Solid meting below its melting point

6.Solid and liquid together at the melting point with no net freezing or melting.

7.Gas condensing below its condensation point

8.Liquid and gas together at the boiling point with no net condensation or vaporisation

9.Liquid freezing above its freezing point liquid vaporizing above its boiling point.

The processes which are spontaneous are as follows:

• Solid melting above its melting point.

• Liquid freezing below its freezing point.

• Gas condensing below its condensation point.

• Liquid vaporising above its boiling point.

The processes which are non-spontaneous are as follows:

• Liquid vaporising below its boiling point.

• Liquid freezing above its freezing point liquid vaporizing above its boiling point.

• Solid meting below its melting point

• Gas condensing above its condensation point.

The processes which are at equilibrium are as follows:

• Solid and liquid together at the melting point with no net freezing or melting.

• Liquid and gas together at the boiling point with no net condensation or vaporisation.

Ans:

The processes which are spontaneous are as follows:

• Solid melting above its melting point.

• Liquid freezing below its freezing point.

• Gas condensing below its condensation point.

• Liquid vaporising above its boiling point.