One mole of a monatomic ideal gas in a piston-cylinder. Pick a process, add or remove heat, and watch the energy split. The three bars share one scale, so ΔU = Q − W reads straight off the chart.
Change in internal energy ΔU = Q − W
+360 J
Heat in exceeds the work done, so the gas warms.
Heat added to the gas Q
+600 J
Set by the slider below
Work done by the gas W
+240 J
W = P·ΔV — the gas pushes the piston out
Final temperature
328.9 K
started at 300.0 K
Final pressure and volume
101,325 Pa
V = 0.02698 m3 (26.98 L)
Heat added Q+600 J
Slide left of zero to take heat out of the gas.
Monatomic ideal gas · n = 1 mol · R = 8.314 J/(mol·K) · γ = 5/3
CV = 12.47 J/(mol·K) · CP = 20.79 J/(mol·K)
Every run starts from 300.0 K, 101,325 Pa, 0.02462 m3.
Tip: set the same Q on isochoric and isobaric. The heat is identical, but the isobaric run spends part of it pushing the piston — so it ends up cooler.