Justify whether the following closed system processes have ?U, q, w and ?H increase, decrease or remain the same (0).
a) a gas (closed system) is expanded isothermally (gas pressure remains under 5atm of pressure)
b) temperature of gas (closed system) is decrease while its volume remains constant.
C) Ne(1 mole, gas,1 bar,473k)-------Ne (1 mole, gas,1 bar,273k) where the external pressure is equal to 1 bar too.
d) a gas expands in a vacum surrounding(e.g Outer space)