Which gas is easier to compress, the ideal gas or a real gas?
Let's use the van Der Waals equation for this. (Real gasses also described elegantly by the Viral equation)


You were false that &quot;pressure of a real gas is less than that of the ideal gas&quot;. It is greater. Also the volume is smaller.

Thus if it has a higher pressure and smaller volume, it typically is harder to compress (i.e. the compression factor increases) but it also depends on temperature. Here is a nice plot of compression factors vs temp for some common gasses from the cambridge chem guide.
http://www.chemguide.co.uk/physical/kt/realgases.html