Question

What is the volume of 28.0 g of nitrogen gas at STP?

Answer 1

Numer of moles = mass / molar mass

number of moles of 28.0g of N2 = 28.0g/28.014g/mol = 0.9995mol

standard temperature = 0℃ = 273.15K

standard pressure = 1bar = 0.9869atm

Ideal gas equation is

PV = nRT

P = Pressure, 0.9869atm

V = volume , ?

n = number of moles , 0.9995mol

T = temperature , 273.15K

V = nRT/P

= 0.9995mol × 0.082057(L atm /mol K) × 273.15K/ 0.9869atm

= 22.7L

Therefore

Volume of Nitrogen gas at STP = 22.7L

Note : If standard pressred is considered as 1atm ( as per the old norms ) , the answer is 22.4L .