Question

If 1.0 kcal of heat is added to 1.2 L of O₂ in a cylinder of constant pressure of 1 atm, the volume increases to 1.5 L. Calculate ∆E and ∆H of the pressure.

Answer 1

∴ 0.03 kJ = –7.18 × 10^–3 kcal 

∆E = Q + W

= 1 – 7.8 × 10^–3

= 0.993 kcal 

∆H = ∆E + ∆(PV)

= ∆E + P∆V

= 0.993 + 7.8 × 10^–3 

= 1 k Cal