Question

Given, $AlC{{l}_{3}}+N{{H}_{4}}OH\to X$; X is?
A. A white gelatinous precipitate
B. Soluble in excess$N{{H}_{4}}OH$
C. Soluble in excess NaOH
D. Amphoteric in nature

Answer 1

Chemical reactions are the processes that happen when there is a chemical change between two substances called reactants due to the breaking and forming of new bonds thereby forming new compounds as products. When a displacement reaction occurs, it results in formation of a new compound as a precipitate.

Complete answer:
We have been given a reaction equation where aluminum chloride reacts with ammonium hydroxide to form a compound ‘X’. We have to find the property of ‘X’. This can be determined by detecting the type of the reaction happening between aluminum chloride and ammonium hydroxide.
The reaction between ammonium hydroxide and aluminum chloride occurs in the form of a displacement reaction which is a type of double displacement reaction. The positive cation and the negative anion from both the reactants switch or replace each other’s positions to form products.
So, the reaction will be double displacement as:
$AlC{{l}_{3}}(aq)+3N{{H}_{4}}OH(aq)\to Al{{(OH)}_{3}}(s)+3N{{H}_{4}}Cl(aq)$
The solid formed of aluminum hydroxide is a precipitate and in the form of a white gelatinous ppt.
Therefore, in the given reaction X is $Al{{(OH)}_{3}}$ which is a white gelatinous precipitate.

So, option A is correct.

Note:
Displacement reactions often result in forming one of the products as a precipitate. The reaction will have $Al{{(OH)}_{3}}$ as X which is not soluble in excess $N{{H}_{4}}OH$ as the precipitate is formed in it. The product is also not soluble in NaOH and is neither amphoteric in nature as it is a precipitate.