Question

Amphoteric hydroxides are completely insoluble in __ (neutral/acidic) solution.

Answer 1

Hint: Those compounds which on ionization produce \[{H^ + }\] ions, are known as acids.
Bases: Those compounds which on ionization produce $O{H^ - }$ ions, are known as bases.
Amphoteric Compounds: Those compounds which can react with both acids and bases are known as amphoteric compounds.

Complete step by step answer:
First of all we will discuss acids, bases and amphoteric compounds.
Acids: Those compounds which on ionization produce \[{H^ + }\] ions, are known as acids. They are sour in taste. Acids change the color of litmus from blue to red. When they react with bases then they become less acidic.
Bases: Those compounds which on ionization produce $O{H^ - }$ ions, are known as bases. They are slippery in nature. Bases change the color of litmus from red to blue. When they react with acids then they become less basic.
Amphoteric Compounds: Those compounds which can react with both acids and bases are known as amphoteric compounds.
Hydroxides: The compounds in which metals or non-metals are attached with hydroxide group, are known as hydroxides.
Generally metal hydroxides are amphoteric hydroxides. For example: ferric hydroxides and aluminium hydroxide. They are also known as neutral hydroxides. They are very less soluble.
They are very less soluble in solutions which have acidic as well as basic medium i.e. neutral solution. Amphoteric hydroxides are soluble in charged medium i.e. acidic or basic medium. If only one medium is either basic or acidic then amphoteric hydroxides are soluble. For example: aluminium hydroxide in acidic medium: $3HCl + Al{(OH)_3} \rightarrow AlC{l_3} + 3{H_2}O$ and in basic medium: $Al{(OH)_3} + O{H^ - } \to Al{(OH)_4}^ - $.
Hence when amphoteric hydroxides are mixed with acidic or basic solutions then they are soluble in this medium but when they are mixed in neutral medium i.e. neither acidic nor basic then they are very less soluble or insoluble. So the full statement of the question is as:
Amphoteric hydroxides are completely insoluble in neutral solutions.

Note:
Oxides are those in which metals or non-metals are attached with an oxide group. Generally, metals when burned in air form metal oxides. For example: when magnesium burns in air it forms magnesium oxide.