Answer:
1.0 × 10⁻⁹ M.
Explanation:
<em>∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.</em>
[H₃O⁺] = 1.0 x 10⁻⁵ M.
<em>∴ [OH⁻] = 10⁻¹⁴/[H₃O⁺]</em> = 10⁻¹⁴/(1.0 x 10⁻⁵ M) = <em>1.0 × 10⁻⁹ M.</em>
The balanced equation for
Ca(OH)2 + H3PO4→ Ca3(PO4)2 + H2O is
3 Ca(OH)2 +2 H3PO4→ Ca3(Po4)2 + 6 H2O
3 moles of Ca(OH)2 reacted with 2 moles of H3PO4 to form 1 mole of Ca3(PO4)2 and 6 moles of H2O