Aluminum hydroxide reacts with phosphoric acid to give AlPO₄. The substance is used industrially in adhesives, binders, and cements.
(a) Write the balanced equation for the preparation of AlPO₄ from aluminum hydroxide and phosphoric acid.
(b) If you begin with 152 g of aluminum hydroxide and 3.00 L of 0.750 M phosphoric acid, what is the theoretical yield of AlPO₄?
(c) If you place 25.0 g of AlPO₄ in 1.00 L of water, what are the concentrations of Al³⁺ and PO₄³⁻ at equilibrium? (Neglect hydrolysis of aqueous Al³⁺ and PO₄³⁻ ions.) K_sp for AlPO₄ is 1.3 × 10⁻²⁰.
(d) Does the solubility of AlPO₄ increase or decrease on adding HCl? Explain.

Transcribed Image Text:

This is a sample of hydrated aluminum phosphate, a min- eral known as augelite. Cengage Leaming/Charles D. Winters