Question

500 ml of Na₂CO₃ solution contains 2.65 g of Na₂CO₃ (mol. mass of Na₂CO₃ = 106). If 10 ml of this solution is diluted to 1 L, what is the concentration of the resultant solution?

Answer 1

Molarity of the available Na₂CO₃ solution

For dilution M₁V₁ = M₂V₂ ⇒ 0.05 × 10 = 1000 × M₂ 

M₂ = 0.0005 M (Molarity of the resultant solution).