Which of the following is a measure of randomness in a system?

Entropy is indeed the measure of randomness or disorder in a system. It quantifies the number of possible microstates corresponding to a given macrostate of the system. The concept reflects how dispersed or spread out the energy is within the system. An increase in entropy indicates an increase in disorder or randomness, meaning that the molecules in the system have more freedom to move and occupy different states.

In thermodynamic terms, as a system undergoes processes, such as heating and mixing, the entropy tends to increase, leading to a higher level of disorder. This is a fundamental principle in understanding spontaneous processes, as systems naturally evolve toward configurations with higher entropy.

In contrast, enthalpy is a measure of the total heat content in a system and does not directly relate to randomness. Temperature is a measure of the average kinetic energy of particles in a system, while pressure relates to the force exerted by gas particles in a given volume. None of these concepts capture the idea of randomness or disorder in the same way that entropy does.