What is the difference betwn molarity and molality ?

1.	What is the difference betwn molarity and molality ?
Answer» Molality (m) : It is the number of moles of the solute dissolved per kilogram (kg) of the solvent. It is denoted by m.{tex}\\therefore{/tex} Molality (m) {tex} = \\frac{{{\\text{No}}{\\text{. of Moles of solute}}}}{{{\\text{Mass of solvent in kg}}}}{/tex}{tex}\\therefore \\,m = \\frac{{{W_2} \\times 1000}}{{{M_2} \\times {W_1}}}{/tex}Where W1 = mass of solventW2 = mass of soluteM2 = Molar mass of solute . Unit is mol/KgMolarity (m): It is the number of moles of the solute dissolved per litre of the solution. It is denoted by M.Molarity {tex} = \\frac{{{\\text{No}}{\\text{. of moles of solute}}}}{{{\\text{Volume of solution in litre}}}}{/tex}{tex}\\therefore \\;M = \\frac{{{W_2} \\times 1000}}{{{M_2} \\times {V_1}}}{/tex}where W2 = mass of solventM2 = molar mass of soluteV = Volume of solution. Unit is mol/LThe molarity and molality of a solution will be nearly same if the mass of solvent is nearly equal to the volume of solution.

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