What is the molarity of Cu2+ in a catalyzed reaction using 3 drops of CuSO4 at .03M in 50.0ml, and what is the molarity of Cu2+ using 6 drops? (Consider the extent of dilution of the 0.1 M CuSO4 solution in preparing the 50 mL reaction solution. Estimate 20 drops/mL.)

My Work:
3drops*1ml/20drops=.15ml
Total ml=50.15=.05015l
Molarity=moles/L
.03molarity*.050l=.0015molesCuSo4
1moleCu2+ to 1 mole CuSo4 (I think?)
so molarity for 3 drops=.0015/.05015=.03M
I know I did something wrong (I think finding the moles) because I got the same Molarity for both 3 and 6 drops, which I know is wrong. Any help, please and thanks!!!

1 answer

The problem is worded funny and I can't tell if the final volume is 50 mL or 50.15 mL.
If 50.15 as you are suggesting then
0.03 M x 0.15 mL/50.15 mL = ?M
0.03 M x 0.30 mL/50.30 mL = ?M

If the final volume is 50 mL then
0.03 x 0.15/50 = ?
0.03 x 0.30/50 = ?