posted by Toni Jones .
A 1.00L sample of seawater contains 19.4g of chloride ions, 10.8 g of sodium ions, and 1.29 g of magnesium ions. How many more moles of chloride ions would be needed to make neutral salts of all the cations in solution?
Convert 19.4 g Cl^- to moles. moles = grams/atomic mass.
Convert 10.8 g Na ions to moles.
Convert 1.20 Mg ions to moles.
Add the + ions and the - ions to make them zero. Don't forget that Mg is a +2 charge and the others are +1.