How will you arrive at the relationship qp = qv + ΔngRT?
Enthalpy change ΔH = qp; where qp = heat change at constant pressure, Internal energy change ΔU = qv; where qv = heat change at. constant volume. Now ΔH = ΔU + PΔV For ideal gases PV = nRT ∴ ΔH = ΔU + (PV2 – PV1) = ΔU + P(V2 – V1) = ΔU + (n2RT – n1RT) = ΔU + RT(n2 – n1) = ΔU + ΔngRT or qp = qv + ΔngRT
