Question

Enthalpy: E is internal energy of the system, P is the pressure, and V is the volume. For a process carried out at constant pressure and only volume changes, (only work allowed is that from volume change) Enthalpy: how much energy was absorbed or released?

a) ΔE = ΔP
b) ΔE = PΔV
c) ΔE = PV
d) ΔE = Q

Answer 1

For a process occurring at constant pressure with only volume changes, the energy absorbed or released can be determined by the enthalpy change, which at constant pressure is equal to the heat added or lost, represented by ΔE = Q.

Step-by-step explanation:

The question is asking how to calculate the energy absorbed or released by a system when a process is carried out at constant pressure with only volume changes. Using the formula Enthalpy (H) = U + P∗V, where U stands for the internal energy, P for the pressure, and V for the volume. At constant pressure, the enthalpy change (ΔH) is the heat of the process, which can be determined by the heat added or lost (Q). Thus, the correct formulation for the energy absorbed or released under these conditions is ΔE = Q (option d), where ΔE represents the change in internal energy of the system. The other options are incorrect because ΔE is not equal to ΔP, PV, or PΔV under these circumstances.