How many grams of a 3% magnesium sulfate solution can be prepared from 100 g of MgSO4 * 7H2O?

1. Find the mass fraction of magnesium sulfate in the crystalline hydrate:

ww cr (MgSO4) = M (MgSO4): M (MgSO4 * 7H2O);

M (MgSO4 * 7H2O) = 24 + 32 + 16 * 4 + 7 * 1 * 2 + 7 * 16 = 246 g / mol;

M (MgSO4) = 24 + 32 + 4 * 16 = 120 g / mol;

ww cr (MgSO4) = 120: 246 = 0.4878;

2.Let’s find the mass of magnesium sulfate in a portion of crystalline hydrate weighing 100 g:

m (MgSO4) = ww cr * m (cr) = 0.4878 * 100 = 48.78 g;

3. find the mass of the solution:

m solution (MgSO4) = m (MgSO4): w in solution (MgSO4);

m solution (MgSO4) = 48.78: 0.03 = 1626 g.

Answer: 1626