Question

Calculate the density of nitrogen gas, in grams per liter, at stp.

Answer 1

Standard temperature is 273 K

Standard pressure is 1 atm

We use the ideal gas equation to find out density of nitrogen gas in g/L

Ideal gas equation:

$PV = nRT\\ PV = (\frac{Mass}{Molar mass)}RT\\ P(Molar mass) = (\frac{Mass}{Volume})RT\\ \frac{Mass}{Volume}=\frac{P(molar mass)}{RT} \\ Density = \frac{P(Molar mass)}{RT}$

Molar mass of $N_{2} = 28 g/mol$

Pressure = 1 atm

Temperature = 273 K

$Density = \frac{(1atm)(28 g/mol)}{(0.08206 \frac{L.atm}{mol.K})(273 K)}$

= 1.25 g/L

Therefore, density of nitrogen gas at STP is 1.25 g/L