Question

What is the physical significance of free energy?

• A. A decrease in free energy is the measure of the useful work done by the system
• B. An increase in free energy is the measure of the useful work done by the system
• C. A decrease in free energy is the measure of the useful heat loss by the system
• D. None of these

Answer 1

The correct option is A A decrease in free energy is the measure of the useful work done by the system

Decrease in Gibb's function at constant temperature and pressure in a process gives an estimate or measure of maximum non-PV work (useful work) which can be obtained from system in reversible, manner. The example of non-PV work is electrical work done by chemical battery.