The enthalpy of vaporization of a liquid is 32.00 kJ/mol at 350 K. What is Δ U if Δ ng = 1 ? ( R = 8.314 J/mol·K )
For Δ ng = 1 , RT = 8.314 × 350 × 10⁻³ = 2.9099 kJ . Using Δ H = Δ U + Δ ng RT , Δ U = 32.00 - 2.9099 = 29.09 kJ/mol .
Ref: NCERT Class 11 Chemistry > Chapter 5: Thermodynamics > Topic: Heat Capacity and Calorimetry and Measurement of Enthalpy