[ A l ( H 2 O ) 6 ] 3 + ⇋ H 2 O [ A l ( O H ( H 2 O ) 5 ] 2 + + H 3 O + {\displaystyle \mathrm {[Al(H_{2}O)_{6}]^{3+}\quad {\overset {H_{2}O}{\leftrightharpoons }}\quad [Al(OH(H_{2}O)_{5}]^{2+}+H_{3}O^{+}} }