Question

Derive the relation of delta H=Delta U+delta ngRT

Answer 1

Answer:

Thermodynamics. Derive a relationship between ∆H and ∆U. Let H1 be the enthalpy of a system in the initial state and H2 be the enthalpy of a system in the final state. ... Thus, the change in enthalpy at constant pressure is equal to the increase in internal energy plus pressure-volume work done (work energy).

Answer 2

Consider a chemical reaction occurring at constant temperature, T and constant pressure, P. Now, let’s say that the volume of the reactants is VA and the number of moles in the reactants is nA. Similarly, the volume of the products is VB and the number of moles in the product is nB.

We know that according to the ideal gas equation,

Pv=nRT

pvA=nART                                

pvB= nBRT

Thus

pvB- pvA = nBRT- nART

p(vB- vA) =RT(nB-nA)

p∆v =∆ngRT

∆H=∆U +p∆v

∆H=∆U+∆ngRT

Hope it helped! :)