Question

How many grams of NaOH (molar mass 40.0) are required to prepare 2.5L of 0.750 M solution?

Answer 1

Given the volume of NaOH solution, V = 2.5 L

Concentration of NaOH solution, M = 0.750 M = 0.750 mol/L

Hence moles of NaOH in the solution = MxV = 0.750 mol/L x 2.5 L = 1.875 mol

Given the molar mass of NaOH = 40.0 g/mol

Hence mass of NaOH required = 1.875 mol x 40.0 g/mol = 75.0 g (answer)