Question

A storage tank at STP contains 24.4 kg of nitrogen (N2)

1. ) What is the pressure if an additional 27.6 kg of nitrogen is added without changing the temperature?

Answer 1

Initial mass of N₂ = 24.4 kg = 24400 g

Hence, No.of moles of N₂ = (24400 g) / (28 g/mol) = 871.428 mol

Hence, Volume of the tank is given by:

PV = nRT

V = (nRT) / (P)

V = (871.428 * 0.0821 * 273 K) / (1 atm)

V = 19531.59 L

Now extra Nitrogen is added.

Total mass of N₂ = 24.4 + 27.6 kg = 52 kg = 52000 g

Hence, No.of moles of N₂ = (52000 g) / (28 g/mol) = 1857.14 mol

Hence, Pressure is given by:

PV = nRT

P = (nRT) / (V)

P = (1857.14 * 0.0821 * 273 K) / (19531.59 L)

P = 2.1311 atm -------------- (**Answer**)