The compound NF3 has van der Waals constants a = 3.580 atm•L2/mol2 and b = 0.0545 L/mol. Using both the ideal gas law and van der Waals’s equation, calculate the pressure expected for 18 mol of NF3 gas in a 6.00-L container at 30 °C.
Not sure how to approach. Any help appreciated.