Question

Amphoteric hydroxides are almost insoluble in _______ (neutral/acidic) solution.

Answer 1

Metal hydroxides such as $Fe(OH{)}_3$ and $Al(OH{)}_3$ react with acids and bases, they are called amphoteric hydroxide.

These neutral substances have very low solubility.

They react in the following way as $\left[H^{+}\right]$ increases.

$Al\left(H_{2}O{)}_3\right(OH{)}_3+H_3{O}^{+}\to Al\left(H_{2}O{)}_4\right(OH{)}_2^{+}+HOH$

When the pH increases, the following reactions take place

$Al\left(H_{2}O{)}_3\right(OH{)}_3+O{H}^{-}\to Al\left(H_{2}O{)}_2\right(OH{)}_4^{-}+H_{2}O$

The charged species are soluble in water.

As a result, amphoteric hydroxides dissolve in acidic and basic solutions and have very low solubility in neutral solutions.

Hence, the correct answer is neutral.