Question

A 2 mL sample of copper (II) sulfate CuSO4 was found to have a concentration of 0.004M.

How many moles of copper are in the solution?

How many moles of sulfate are in the solution?

How many grams of copper are in the sample?

Write the concentration in grams of copper per milliliter of solution.

If 1 mL of the sample is added to a 50 mL volumetric flask and diluted with water, what is the concentration of the diluted solution?

How many moles of copper are in the diluted solution?

Answer 1

0.004 moles of copper are in the solution.

0.004 moles of sulfate are in the solution. (Because both are mono ionic)

Molar mass of Cu 63.456 g/mol.

                           = 0.004 x 63.456 x 2 /1000 = 0.000507648 gm of CusO4 presents in 2 ml solution.

                           = 0.000253824 gm of copper presents per milliliter of solution.

If 1 mL of the sample is added to a 50 mL volumetric flask and diluted with water,

                          = 1 x 0.004 /50 = 8 x 10^-4 M

concentration of the diluted solution = 8 x 10^-4 M

8 x 10^-4 moles of copper are in the solution.