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smugrl
Nov 22, 2009, 01:01 PM
Determine the number of mL of .03 M phosphoric acid required to neutralize 25.00 mL of .015 M calcium hydroxide. Balanced equation = 3Ca(OH)2 + 2H3PO4 ---> Ca3(PO4)2 + 6H2O

Unknown008
Nov 22, 2009, 01:20 PM
1. Find the number of moles of Ca(OH)2.
2. Use your balanced equation to find the mole ratio of Ca(OH)2 and H3PO4.
3. From the ratio, find the amount of moles of H3PO4 which reacts.
4. Using the concentration and amount of moles the volume becomes easy.

Post you answer! I hope it helped! :)

smugrl
Nov 22, 2009, 08:36 PM
.025L * .015 mol Ca(OH)2= 3.75 * 10^-4 mole Ca(OH)2

3.75 * 10^-4 * (2/3) = 2.5 * 10^-4 mole H3PO4

2.5 * 10^-4/.03= .08333 L * 1000 = 8.33 mL

Helped a LOT. Thanks!

Unknown008
Nov 22, 2009, 11:38 PM
Right! It's perfect! :)

You're welcome! :)