Question

Thermodynamics equilibrium involves

• A. Chemical Equilibrium
• B. Thermal equilibrium
• C. Mechanical equilibrium
• D. All the above simultaneously.

Answer 1

The correct option is D

All the above simultaneously.

Thermodynamics Equilibrium

1. It is a condition or state of a thermodynamic system in which the properties of the system do not change over time and can only be changed at the expense of other systems.
2. It describes the feasibility of a chemical reaction as well as the energy changes related to a chemical reaction.

Explanation for the correct option:

In the case of option D,

For a system to be in thermodynamic equilibrium:

1. Every part of the system must have the same temperature. This means there should be no change in the temperature of the object. The object should be in Thermal Equilibrium
2. There should be no net imbalanced forces on any element of the system, or on the entire system. The object should be in mechanical equilibrium
3. Chemical reactions should not cause any changes. There should be no chemical changes in systems. The object should be in chemical equilibrium.
4. A system to be in thermodynamic equilibrium should be in chemical Equilibrium, thermal equilibrium, and mechanical Equilibrium.

Hence, option (D) is correct.

Explanation for the incorrect option:

In the case of option A,

1. Chemical Equilibrium is the state of a system in which the reactant and product concentrations do not change over time and the system's properties remain unchanged.
2. Thermodynamic equilibrium involves chemical equilibrium.
3. If a system is just in chemical equilibrium but neither in thermal equilibrium nor in mechanical equilibrium then the system is not in thermodynamic equilibrium.

Hence, option A is incorrect.

In the case of option B,

1. The condition in which two substances in physical contact exchange no heat energy is known as thermal equilibrium.
2. Thermodynamic equilibrium involves thermal equilibrium.
3. If a system is just in thermal equilibrium but neither in chemical equilibrium nor in mechanical equilibrium then the system is not in thermodynamic equilibrium.

Hence, option B is incorrect.

In the case of option C.

1. Mechanical Equilibrium- The system is considered to be in mechanical equilibrium when no mechanical work is done by one part of the system on any other part of the system.
2. Thermodynamic equilibrium involves mechanical equilibrium.
3. If a system is just in mechanical equilibrium but neither in chemical equilibrium nor in thermal equilibrium then the system is not in thermodynamic equilibrium.

Hence, option C is incorrect.

So, thermodynamics equilibrium involves chemical equilibrium, thermal equilibrium, and mechanical equilibrium.

Hence, options (A), (B), and (C) are incorrect.