Question

Explain the term : Mole

Answer 1

The mole is a unit of measurement for the amount of substance. Moles give us a consistent method to convert between atoms/molecules and grams.
The mathematical expression for calculating moles is expressed as:
moles = mass / molar mass

We can express moles in terms of molecular mass, number of atoms/molecules and in terms of volume.

• 1 mole of a pure substance has a mass in grams equal to its molecular mass.
• 1 mole contains the same number of particles as there are in 12g of carbon-12 atoms. This number is called Avogadro’s number and is equal to 6.023 × 10²³ particles.1 mole of a gas occupies a volume of: 22.4 litres at S.T.P.

For example: 1 mole of sodium atom has mass 23 g. It contains 6.023 × 10²³ atoms and occupies 22.4 litres of volume at S.T.P.