Enthalpy change being independent of the path taken is a consequence of enthalpy being a what?

• A. State function
• B. Property at constant volume
• C. Kinetic energy
• D. Temperature dependent

Answer: (A)

The main idea is that enthalpy is a state function. That means its value depends only on the current state of the system (things like temperature, pressure, and composition) and not on how you got from one state to another. Enthalpy is defined as H = U + PV, and both U (internal energy) and PV are determined by the state variables. So the difference in enthalpy between the initial and final states is fixed, regardless of the path taken between them. This is why you can break a process into steps and add the enthalpy changes of each step, and you’ll still get the same total ΔH. It also underpins Hess’s law for enthalpy changes and the practical point that at constant pressure the heat exchanged equals ΔH. The other options don’t fit because kinetic energy describes motion, not heat content; enthalpy being tied to a constant-volume property isn’t what guarantees path independence; and while enthalpy does depend on temperature, the key reason for path independence is that enthalpy is a state function.