Question

Mole fraction of solute in an aqueous Solution of NaOH is 0.02. Density of Solution is 1.08 g / mL. Calculate the molarity of the Solution. 

Answer 1

Moles of solute = 0.02, 

Moles of solvent = 0.98 

Mass solute = 0.02 x 40 = 0.8 

Mass solvent = 0.98 x 18 = 17.64 

Mass Solution = 17.64 + 0.8 = 18.44 

Volume of Solution = 18.44 / 1.08 = 17.07 

Molarity = 0.02 x 1000 / 17.07 = 1.17