What is Molarity,Molality,Normatiy?
Molarity, molality and normality are three different terms that are used to express the concentration of a solution.
Molarity is defined as the number of moles of solute present per litre of the solution. Thus
Molarity = number of moles of solute / Volume of solution (in litres)
Here number of moles = mass of solute / molar mass of solute
Molality is defined as the number of moles of solute per Kg of the solvent. Thus
Molality = number of moles of solute / Mass of solvent (in Kg)
Normality of a solution is defined as number of gram equivalents of solute present per litre of the solution. Thus
Normality = Number of gram equivalents of solute / Volume of solution in litres
The number of gram equivalents are defined as
= mass of solute / equivalent mass
Further the equivalent weight of an element/compound is its atomic/molecular weight divided by its valence (number of electrons gained or lost by one molecule or ion of the substance in the reaction).