Question

A student titrates a solution containing 0.050 moles of calcium hydroxide with phosphoric acid. How many moles of phosphoric acid need to be added to reach the equivalence point?

Answer 1

Answer:

The answer to your question is 0.33 moles of H₃PO₄

Explanation:

Data

moles of Ca(OH)₂ = 0.050

moles of H₃PO₄ = ?

Process

1.- Write the balanced chemical equation

           3Ca(OH)₂  +  2H₃PO₄    ⇒   Ca₃(PO₄)₂   +   6H₂O

             Reactants        Elements       Products

                    3                      Ca                     3

                   12                       H                     12

                   14                      O                      14

2.- Calculate the moles of phosphoric acid

      3 moles of calcium hydroxide --------------- 2 moles of phosphoric acid

      0.5 moles of calcium hydroxide -----------   x

      x = (0.5 x 2)/3

      x = 0.33 moles