Enthalpy · H = U + PV
unseel.com · Heat at constant pressure · ΔH = Q_p · Hess's law
U (internal) 0 kJ
PV (make room) 0 kJ
H = U+PV 0 kJ
state standby
Gas (internal energy U)
Piston & PV work
Atmosphere / heat flow
Unseel.com · Enthalpy