Question

Calculate the mass of CuSO4 and water required to prepare 250g of 10% solution of CuSO4.

Answer 1

Answer:

My immediate answer is: with great difficulty .

But if I reword the question to read :

What mass in g of CuSO4 is required to produce 250 mL of 0.01M solution.

Do you see the differences? There is no metric abbreviation gm that can reasonably be used in the context of this question

Molar solutions are prepared based on the volume of the final solution - not the volume of solvent ( THIS IS IMPORTANT)

The common starting point for such a solution is the blue crystalline CuSO4 . 5H2O

Molar mass CuSO4.5H2O = 249.6850 g/mol

You want to make a 0.01M solution

Mass of CuSO4.5H2O required = 249.6850 g/mol *0.01 mol 2.4968 g/L

But you wish to prepare 250 mL solution = 0.250 L

Mass = 2.4968 g/L * 0.250L = 0.6242 g CuSO4.5H2O required.

Explanation: