Question

2.46 g of sodium hydroxide (molar mass = 40) are dissolved in water and the solution is made to 100 cm³ in a volumetric flask. Calculate the molarity of the solution.

Answer 1

Given: Mass of NaOH = 2.46 g

Molar mass of NaOH = 40 g/mol

Volume of solution = 100 cm³ = 0.100 L

Moles of NaOH = `2.46/40`

Moles of NaOH = 0.0615 mol

Molarity (M) = `"Moles of solute"/"Volume of solution in L"`

= `0.0615/0.100`

= 0.615 mol/L

∴ The molarity of the solution is 0.615 mol/L.