Question

Calculate the mass of ammonium chloride required to prepare 25 mL of a 2.0 M solution, and the mass of calcium chloride required to prepare 25 mL of a 2.0 M solution.

Answer 1

Calculation

To prepare 2 M of 25 ml NH4Cl solution

mass of NH4Cl required = molarity x molar mass c volume (L)

                                      = 2 M x 53.5 g/mol x 0.025 L

                                      = 2.675 g

To prepare 2 M of 25 ml CaCl2 solution

mass of CaCl required = molarity x molar mass c volume (L)

                                   = 2 M x 110.98 g/mol x 0.025 L

                                 = 5.049 g