Question

Molar volume is the volume occupied by 1 mol of any (ideal) gas at standard temperature and pressure (STP : 1 atmospheric pressure, 0 °C). Show that it is 22.4 litres

Answer 1

The ideal gas equation relating pressure (P), volume (V), and absolute temperature (T) is given as:

PV = nRT

Where,

R is the universal gas constant = 8.314 J mol-1 K-1

n = Number of moles = 1

T = Standard temperature = 273 K

P = Standard pressure = 1 atm = 1.013 × 105 Nm–2

∴ $V=\frac{nRT}{P}$

$=\frac{1×8.314×273}{1.013×10^5}$

= 0.0224 m3

= 22.4 litres

Hence, the molar volume of a gas at STP is 22.4 litres.