Question

How many grams of CuSO4 5 H20 are needed to make 1 liter of a 2% (w/v) CuSO4. REPORT TO THE NEAREST 1/10 G.

Answer 1

19.9 grams of
`CuSO_4.5H_2O` will be needed.

Step-by-step explanation:

Required strength of the solution = 2% (w/v)

This means that 2 gram of solute in 100 ml of solution.

Mass of
`CuSO_4.5H_2O` = 2 g

Moles of
`CuSO_4.5H_2O` =
`(2 g)/(249.68 g/mol)=0.008010 mol`

Volume of the solution = 100 mL = 0.1 L

Molarity of the solution:

`M=(0.008010 mol)/(0.1 L)=0.08010 mol/L`

0.08010 moles of
`CuSO_4.5H_2O` are present 1 l of the solution.

Then mass of 0.08010 moles of
`CuSO_4.H_2O` will be:

0.08010 mol × 249.68 g/mol = 19.9993 g≈ 19.9 g

19.9 grams of
`CuSO_4.5H_2O` will be needed.