A system absorbs 20 kJ heat and does 10 kJ of work. The internal energy of the system — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

According to the First Law of Thermodynamics: Δ U = q + w. Heat absorbed q = +20 kJ. Work done BY the system w = -10 kJ. Thus, Δ U = 20 - 10 = +10 kJ. So the internal energy increases by 10 kJ.