Physics: What is the pressure?

Question

If a tank has 2.50 g of N₂ (nitrogen atom has 14 nucleons) and a volume of 1950 cm³ and it is held at 142 ⁰ C, what is the pressure?

Answer 1

We use P = nRT/V        where n = 2.50/(2*14) moles = 0.08929

                                            R = 0.0821 L*atm*mol^-1K^-1

                                            T = 142 + 273 = 415 K (Kelvins)

                                            V = 1950/1000 = 1.950 L

           P = 1.56 atm