How many moles of gas will occupy 3.5 L container at 315 K, if the pressure is 2.1 atm?

Answer: 3 moles

Explanation:

Using the ideal gas equation; PV = nRT

P = Pressure = 2.1 Atm V = Volume = 3.5L T = Temperature = 315K

n = no of moles

R = Gas constant = 0.08206 L. atm. mol-1. K-1

Making 'n' the subject of the formular, we then have;

n = PV / RT

= 2.1 Atm x 3.5L / 0.08206 L. atm. mol-1. K-1 x 315K

= 7.35 / 25.849

= 0.28 approx 3moles