van der waals question!?

Question

Water has a van der Waals constants of a = 5.464 L·atm/mol2 and b = 0.03049 L/mol. What is the pressure of 7.70 moles of water vapor in a 1.10 L container at 100.0°C?

Answer 1

I think your unit of a is not correct. Maybe a = 5.464 L^2·atm/mol^2.
The van der Waals equation is:
(p + n^2a/V^2)(V - nb) = nRT
Hence: p = nRT/(V-nb) - a(n/V)^2
= 7.70*0.08206*373/(1.10-7.70*0.03049)-5.464*(7.70/1.10)^2
=4.66 (atm)