A solution of NaOH (Molar mass 40gmol−1) was prepared by dissolving 1.6g of NaOH in 500cm3 of water. Calculate molarity of NaOH solution.
1 mol of NaOH has a mass of 40g. So
Moles of NaOH=1.6g of NaOH×1molNaOH40gNaOH=0.04 mol NaOH
Litres of solution =500ml solution ×1LSolution1000mlSolution=0.5 L Solution
Molarity =molesofSolutelitresofsolution
=0.040.5 mol/L
=0.08 mol/L