It requires 30ml of .5M H3PO4 to titrate 45ml of Ca(OH)2 to the equivalence point. What is the M of the base?
Write the equation and balance it.
2H3PO4 + 3Ca(OH)2 ==> Ca3(PO4)2 + 6H2O
Check that to make sure it's right.
mols H3PO4 = L x M = ?? mols H3PO4.
(30 mL is 0.030 L)
Using the balanced equation convert mols H3PO4 to mols Ca(OH)2.
Now convert mols and mL of Ca(OH)2 to Molarity. M = mols/L. I get 0.5 M for the base.