Question

I'm going crazy please help me out

part 1 of 2 Determine the mass of anhydrous copper(II) sulfate that must be used to prepare 250 mL of 2.01 M CuSO4(aq). Which i found to be 80.204g

part 2 of 2
Determine the mass of CuSO4.5H2O that must be used to prepare 250 mL of 2.01 M CuSO4(aq).

another question
Na3AsO4 is a salt of a weak base that can accept more than one proton. If 30.2 g of Na3AsO4 is dissolved in water to make 250 mL of solution, how many moles of sodium cations are in the solution?
Answer in moles

Answer 1

1. 80.204 is ok except you are not allowed that many significant figures.

2. This one is done just like #1 but instead of molar mass being 159.61 it is 159.61+(5*80)= ?? or about that. YOu need to check that out.

3. moles Na3AsO4 = grams/molar mass.
moles Na^+ = 3x that. The amount of water in which it is places makes no difference.

Answer 2

of 1.79 M CuSO4(aq).