The correct option is
D All the above simultaneously.
Thermodynamics Equilibrium
- 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.
- 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:
- 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
- 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
- Chemical reactions should not cause any changes. There should be no chemical changes in systems. The object should be in chemical equilibrium.
- 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,
- 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.
- Thermodynamic equilibrium involves chemical equilibrium.
- 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,
- The condition in which two substances in physical contact exchange no heat energy is known as thermal equilibrium.
- Thermodynamic equilibrium involves thermal equilibrium.
- 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.
- 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.
- Thermodynamic equilibrium involves mechanical equilibrium.
- 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.