Conversion guide
For monovalent ions, 1 equivalent = 1 mole
For divalent ions, 1 Eq = 0.5 mol
For trivalent ions, 1 Eq = 0.333 mol
so for every 1 Eq, there is 1 mole. now that its simple, we convert the given data into moles. then multiply by 1.5 to get the value for 1.5 L