Looking at an ion, how can you tell whether hydrolysis will occur or not?

Oct 10, 2016

Cations of weak bases and Anions of weak acids are hydrolysed

Explanation:

If the ion is a cation that forms an weak base combining with required number of $O {H}^{-}$ion/s in water then the its solution becomes acidic one due to hydrolysis. For example $F {e}^{3 +}$ ion

$F {e}^{3 +} + 3 {H}_{2} O \to F e {\left(O H\right)}_{3} + 3 {H}^{+}$

Again when an anion of a salt of weak acid interacts with water it combines with the ${H}^{+}$ions of water thereby enhancing the number of $O {H}^{-}$ ions in water and thus it makes the solution basic in nature.
For example Acetate ion $C {H}_{3} C O {O}^{-}$

$C {H}_{3} C O {O}^{-} + {H}_{2} O \to C {H}_{3} C O O H + O {H}^{-}$

Inference

Cations of weak bases and Anions of weak acids are hydrolysed