Calculate the change in internal energy (ΔU) for a system that is giving off 25.0 kJ of heat and is changing from 12.00 L to 6.00 L in volume at 1.50 bar. (Remember that 100 J = 1 L bar)

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Quizplus · Accepted Answer

The work done on the system is calculated using W = -PΔV = -1.50 bar * (6.00 L - 12.00 L) = 9.0 L bar = 0.9 kJ. The system gives off 25.0 kJ of heat, so ΔU = q + W = -25.0 kJ + 0.9 kJ = -24.1 kJ.

Calculate the Change in Internal Energy (ΔU) for a System