The pressure of real gases is less than that of ideal gas because of

Explanation

At low pressure, volume V is very large and hence the correction term (b) a constant of small value) can be neglected in comparison to very large of V. thus the van der waals. equation for 1 mole of a real gas
`(P+(a)/(V^(2)))(C-b)=RT` my be written as `(P+(a)/(V^(2)))(V)=RT`
or `Pv+(a)/(V)=RT or PV RT-(a)/(V)`
for large V (at very low pressure) `(a)/(V)` is very small and can be ignored.
`:.` PV becomes RT at very low pressures.