Question

How much water needs to be added to 100 mL of a 20%w solution of copper (II) sulfate to prepare a 0.01-M solution?

Answer 1

Answer:

12430mL of water must be added

Explanation:

To solve this question we need to convert the 20%w of CuSO₄ to molarity. Then, using the diulution factor we can find the amount of water required:

20g CuSO₄ / 100mL * (1mol / 159.609g CuSO₄) = 0.1253 moles / 100mL = 0.1253mol / 0.1L =

1.25M is the concentration of CuSO₄. To dilute this concentration to 0.01M, the dilution factor must be of:

1.25M / 0.01M = 125 times must be diluted the solution.

As the volume of the concentrated solution is 100mL, the total volume of the solution to have a 0.01M solution must be of:

100mL * 125 times = 12530mL is the final volume of the solution. That means the amount of water added must be of:

12530mL - 100mL =

12430mL of water must be added