Aluminium hydroxide dissociates according to the equations Al(OH)3(aq)‌⇌Al(OH)3(aq) ‌⇌Al3+(aq)+3OH−(aq) Let the solubility of Al(OH)3‌‌′=S‌mol‌L−1 ∵Al(OH)3(aq)‌⇌Al3+(aq)+3OH−(aq) ‌S‌S ∵‌Ksp‌=[Al3+][OH−]3 ∵‌Ksp‌=(s)(3s)3=27s4 ‌ hence, ‌‌Ksp‌=27s4