Question

A solution is made by mixing 90.6 g of magnesium sulfate heptahydrate with 2320.0 g of water.
690.00 mL of the solution has a mass of 745.20 g.

1. What is the molarity of the magnesium sulfate solution?

2. What is the molarity of the magnesium ion?

3. What is the molality of the magnesium sulfate solution?

Answer 1

See your post bedlow for #1.
2. MgSO4.7H2O has 1 mol Mg for each mols MgSO4.7H2O; therefore, M mg^+ = M MgSO4.7H2O

3. m = mols MgSO4.7H2O/kg solvent.
Post your work if you get stuck.

Answer 2

The post that I followed for #1 ended up with the wrong answer

Answer 3

Let me look at how you arrived at the answer.