A real gas has reduced pressure pr reduced temperature Tr an

A real gas has reduced pressure p_r, reduced temperature T_r, and compressibility factor Z. In which case it is reasonable and accurate enough to assume ideal gas behavior? Provide a brief explanation and example.

A) if Z<<1
B) if p_r<<1 or T_r>2
C) if p_r>1 and T_r<2
D) if p_r =~1 or T_r =~1

Solution

for ideal gas, compressilbility factor (Z) = 1,

and reduced temperature = T/Tc and reduced pressure = P/Pc, so Tr and Pr also becomes almost equal to 1 that means temperature og the gas has attained critical temperature and same goes to pressure and that mean they can behave like ideal gas.

so option (D) Pr and Tr values almost equal to 1