Calorimetry - Chemistry

Question

Calculate the internal energy (in Joules) of a system that loses 340.8 J that is compressed with a pressure of 2.13 atm from 4.930 L to 1.00 L.

Answer 1

∆U = q + w

∆U = change in internal energy = ?

q = heat = -340.8 J (negative sign since system is losing heat)

w = work = -P∆V = (-2.13 atm)(-3.930 L) = 8.37 Latm x 101.324 J / L atm = 848 J (positive sign since work is being done on the system)

∆U = -341 J + 848 J = +507 J