Question

Define mole. Name two parameters which a mole represents.

Answer 1

Mole:

• The amount of a substance that consists of as many number of particles as there are atoms in exactly 12 g of C-12 (Carbon-12) isotope of Carbon is called one mole.
• These particles can be atoms, ions, molecules, formula units etc. depending upon the nature of the substance (atomic, ionic, molecular, salt etc.)
• Number of atoms present in exactly 12 g of C-12 (Carbon-12) isotope of Carbon is called Avogadro number and its value is 6.023×10²³.

Two parameters which a mole represents are:

• Gram atomic mass or Gram molecular mass: The weight in grams which is present in one mole of a substance is called gram atomic mass (if the substance consists of atoms) or gram molecular mass (if the substance consists of molecules). i.e.;1 mole = Gram atomic or molecular mass
• Number of particles: The number of particles contained in one mole of a substance is 6.023×10²³. i.e.;1 mole= 6.023×10²³ particles

Example: 1 mole of Carbon (C)= 12 g mol^-1 of Carbon atoms= 6.023×10²³ number of Carbon atoms