Question

What is the concentration of the Cu⁺² ion, expressed as molarity, in a solution prepared by dissolving 1.25g of CuSO₄ * 5H₂O in enough water to give 50.0 mL of solution?

Answer 1

mass of CuSO₄ * 5H₂O = 1.25

moles of CuSO₄ * 5H₂O = 1.25 / 249.685

                                      = 5.006 x 10^-3 mol

volume = 50.0 mL = 0.050 L

Molarity = moles / volume

             = 5.006 x 10^-3 / 0.050

Molarity   = 0.100 M

concentration of the Cu⁺² ion = 0.100 M