Correct Answer – D
At high pressure, all the real gases have `Z gt 1` as these gases are less compressible than an ideal gas. On account of the repulsive forces, these are more difficult to compress. At intermediate pressure, most gases have `Z lt 1`. Thus, real gases show ideal behavior when the volume occupied by the gas is large (at low pressure), so that the volume of the molecules can be neglected in comparision to it. In other words , the behavior of the real gas becomes more ideal when the pressure is very low.