CBSE Class 9 Answered

Mole : A mole is defined as the amount of a substance containing elementary particles like atoms,molecules or ions in 12g of carbon.

Molarity :  It is defined as the number of moles of solute dissolved per litre of solution. It is expressed by the symbol M .Its units are mol/L.

Molality : It is defined as number of moles of solute present per kg of the solvent. It is denoted by symbol “m”. Its units are mol/kg.

Normality:  Normality of a solution is defined as the number of gram equivalents of a solute dissolved per litre of the solution. It is expressed by the symbol N.Its units are gram eq L^-1.