What is the final concentration of hydroxide (OH) ions when 2.00 L of 0.100 M Ba(OH)2 is combined with 1.00 L of 5.00*10^-3 M H3PO4 and allowed to react to completion?
Chemical Equation that's balanced is:
3Ba(OH)2 + 2H3PO4 --> Ba3(PO4)2 +6H20[/B]
The Attempt at a Solution
To start off, i found that H3PO4 is the limiting reactant so used the mols of that to calculate hydroxide ions.
Therefore, 0.005 mols H3PO4 * (6 mols OH/2 mols H3PO4) = 0.15 mols OH
so .15 / 3 liters = 0.05 M (but the answer is 0.128 M!)
Can someone help me![/B]