Question

How many water molecules are associated with Mg^2+ and how many are associated with SO4^2- in the structure MgSO4 x 7H2O?

Please help I am very confused by this question

Answer 1

I looked for a link on the web and didn't find it; however, I associate 6 H2O molecules with Mg^2+ and one with the crystal lattice (or with the sulfate). In the CuSO4.5H2O molecule, there are four H2O molecules associated with the Cu (as Cu(H2O)4^2+) and the fifth one is hydrogen bonded between one of the coordinated H2O molecules and the sulfate ion. My assumption is that MgSO4.7H2O is the same except it's Mg(H2O)^2+ with the other one embedded in the crystal lattice and hydrogen bonded to H2O and sulfate.