Question

List the characteristics of internal energy

Answer 1

Explanation:

Characteristics of internal energy (U):

· The internal energy of a system is an extensive property. It depends on the amount of the substances present in the system. If the amount is doubled, the internal energy is also doubled.

· The internal energy of a system is a state function. It depends only upon the state variables (T, P, V, n) of the system. The change in internal energy does not depend on the path by which the final state is reached.

· The change in internal energy of a system is expressed as ∆U= Uf – Ui

· In a cyclic process, there is no internal energy change. ∆U(cyclic) = 0

· If the internal energy of the system in the final state (Uf) is less than the internal energy of the system in its initial state (Ui), then ΔU would be negative.

ΔU=Uf − Ui = −ve (Uf < Ui)

· If the internal energy of the system in the final state (Uf) is greater than the internal energy of the system in its initial state(Ui), then ΔU would be positive.

ΔU=Uf − Ui = +ve (Uf > Ui)