Question

Calculate the molarity of the 3m aq. solution of NaCl of density 1.25 g ml-1. ​

Answer 1

Molality is 3m ie 3 moles of NaCl in 1000g of water(solvent)

Density of solution = 1.25g/ml

Mass of NaCl = moles x molar mass = 3 x 58.5 = 175.5g

Mass of solution = mass of solute + mass of solvent = 175.5 + 1000 = 1175.5g

Volume of solution = Mass/Density = 1175.5/1.25 = 940.4ml

Molarity = 3/0.9 = 3.33 mol/L