The relation between pressure exerted by an ideal gas (pideal) and observed pressure (preal) is given by the equation Pideal
If pressure is taken in Nm–2, number of moles in mol and volume in m3, Calculate the unit of ‘a’.
What will be the unit of ‘a’ when pressure is in atmosphere and volume in dm3?
It is given that
We know that the unit of p = Nm-2, unit of V = m3, number of moles(n) = mol
Unit of ‘a’ = Nm-2(m3)2/(mol)2 = Nm4mol-4
If we take the unit of p = atm, V = dm3 and n = mol
Then unit of ‘a’ = pV2/n2 = atm(dm3)2/(mol)2 = atm dm6mol-2.