NEET2023ChemistryThermodynamics (C)Actual
Which amongst the following options is the correct relation between change in enthalpy and change in internal energy?
Options
- A∆ H + ∆ U = ∆ n g R
- B∆ H = ∆ U - ∆ n g RT
- C∆ H = ∆ U + ∆ n g RT
- D∆ H - ∆ U = - ∆ n g RT
Correct answer
C. ∆ H = ∆ U + ∆ n g RT
Step-by-step solution
Correct relation between change in enthalpy and change in internal energy is ∆ H = ∆ U + ∆ n g RT As we know, ∆ H = ∆ U + P ∆ V   . . . . ( i ) For an ideal gas PV = nRT For reactant, PV A = n A RT For product, PV B = n B RT Thus, P ( V B - V A ) = ( n B - n A ) RT P ∆ V = ∆ n g RT   . . . . . . ( ii ) Substituting (ii) in (i), we get ∴ ∆ H = ∆ U + ∆ n g RT