Question

A chemist prepares a solution of copper(II) sulfate CuSO4 by measuring out 31.μmol of copper(II) sulfate into a 150.mL volumetric flask and filling the flask to the mark with water.

Calculate the concentration in mol/L of the chemist's copper(II) sulfate solution. Round your answer to 2 significant digits.

Answer 1

number of moles, n = 31 μmol
                                          = 31*10^-6 mol
                                          = 3.1*10^-5 mol

V = 150 mL = 0.15 L

Concentration = number of moles / volume
      = (3.1*10^-5) / 0.15
      = 2.1*10^-4 mol/L

Answer: 2.1*10^-4 mol/L