Posted by ben on .
How many total moles of ions are released when each of the following samples dissolves completely in water?
30.2g of Ba(OH)2 8H2O
Ba(OH)2.8H2O ==>Ba^+2 + 2OH^- + 8H2O
How many mols of the compound did you start with initially. That will be 30.2 g Ba(OH)2.H2O/molar mass of that material.
Then you get 1 mol Ba^+, + 2 mols OH^- + 8 mols H2O. Add them to get total mols. The question may or may not be a trick question. Note that it asks for the total moles of IONS. If that is the intent of the problem, then the 8 mols H2O aren't included in the total since they are not ions.