The balanced chemical equation for the reaction of A(OH)₃ with an acid (assuming a strong acid like HCl) to produce water would be: A(OH)₃ + 3HCl → ACl₃ + 3H₂O This shows that for every 1 mole of A(OH)₃ that reacts, 3 moles of H₂O are produced. Therefore, if 7.5 moles of A(OH)₃ react, the number of moles of H₂O produced is: 7.5 moles A(OH)₃ * (3 moles H₂O / 1 mole A(OH)₃) = 22.5 moles H₂O