What volume (in mL) of 0.404 mol/L calcium hydroxide. Ca(OH)2 (aq), is needed to completely neutralize 78.4mL of 0.373 mol/L phosphoric acid, H3PO4 (aq)

Question

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Answer 1

Start with the balanced equation:

2 H₃PO_4(aq) + 3 Ca(OH)_2(aq) → Ca₃(PO₄)_2(aq) + 6 H₂O_(l)

(1000 mL/1 L) (1 L/0.404 mol Ca(OH)₂) (3 mol Ca(OH)₂/2 mol H₃PO₄) (0.373 mol H₃PO₄/1000 mL) (78.4 mL H₃PO₄) = 1.09 x 10² mL of Ca(OH)₂