# Molar Volume Formula

## What is Molar Volume?

At standard Temperature and Pressure (STP) the molar volumeĀ (Vm) is the volume occupied by one mole of a chemical element or a chemical compound.Ā It can be calculated by dividing the molar mass (M) by mass density (Ļ). Molar gas volume is one mole of any gas at a specific temperature and pressure has a fixed volume.

## Molar Volume Formula

The Molar volume is directly proportional to molar mass and inversely proportional to density. The formula of the molar volume is expressed as

$$\begin{array}{l}V_{m} = \frac{Molar\ mass}{Density}\end{array}$$

Where Vm is the volume of the substance.

The standard temperature used is 273 Kelvin or 0oC,

Standard pressure is 1 atmosphere, i.e., 760 mm Hg.

Experimentally, one mole of any gas occupies a volume of 22.4 litres at STP. The equation can be expressed as

1 mole of gas at STP = 22.4 litres of gas.

Example 1

Calculate molar volume for a sample of the molar mass of the N2Ā if the density of the gas isĀ 1.250 g/L?

Solution:

$$\begin{array}{l}V_{m} = \frac{Molar\ mass}{Density}\end{array}$$

The molar mass of Nitrogen = 28.01 g/mol

Vm = (28.01)/(1.250)

Vm = 22.408 L