Question

4. (2 pts) Calculate the mass of CuSO4 5H20 required to prepare 4.0 mL of 0.040 M CuSO4 solution. Enter your answer in the box and show your work in the space below. Record the value in your lab notebook, as you will need it to complete the experiment. g

Answer 1

volume , V = 4 mL
= 4*10^-3 L


use:
number of mol,
n = Molarity * Volume
= 4*10^-2*4*10^-3
= 1.6*10^-4 mol

Molar mass of CuSO4,
MM = 1*MM(Cu) + 1*MM(S) + 9*MM(O) + 10*MM(H)
= 1*63.55 + 1*32.07 + 9*16.0 + 10*1.008
= 249.7 g/mol

Same would be concentration of CuSO4.5H2O because 1 mol of CuSO4.5H2O gives 1 mol of CuSO4

Molar mass of CuSO4.5H2O,
MM = 1*MM(Cu) + 1*MM(S) + 9*MM(O) + 10*MM(H)
= 1*63.55 + 1*32.07 + 9*16.0 + 10*1.008
= 249.7 g/mol

use:
mass of CuSO4.5H2O,
m = number of mol * molar mass
= 1.6*10^-4 mol * 2.497*10^2 g/mol
= 3.995*10^-2 g
Answer: 4.00*10^-2 g