please explain in details

Tc a = For a gas that obeys the van der Waals equation, the Te and Pe are given by the equations: 8 Pc = 27 Rb 27b2 where a and b Fre the van der Waals constant for the gas. Assuming has a Te of 289 C and Pc of 48.56 atm, (a) determine its van der Waals constants, and (5 marks) (b) calculate the pressure exerted by 10 g of Benzene (C6H6) in one litre flask at 13C. (10 marks)