### Q.2:- 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:-**

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 × 10^{5} Nm^{–2}

∴ *V* = *nRT* / *P*

= 1 × 8.314 × 273 / (1.013 × 10^{5})

= 0.0224 m^{3}

= 22.4 litres

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