Question

The solution of meta aluminate on boiling with ammonium chloride gives a white precipitate of:
a.) \[A{{l}_{2}}{{O}_{3}}\]
b.) \[AlC{{l}_{3}}\]
c.) \[Al{{\left( OH \right)}_{3}}\]
d.) \[NaAl{{\left( OH \right)}_{4}}\]

Answer 1

Hint: To find the answer to this question we have to keep few things in mind which are as follows:
The products formed from a thermodynamic reaction are always stable and lower in energy than the reactants.
If any gaseous product is possible it is mostly formed because it can escape from the reacting mixture and drive the reaction forward.
If any neutralization product or salt which is neutral is possible to form is product it is mostly formed because it is stable.

Complete answer:
The solution of sodium meta aluminate on boiling with ammonium chloride gives a white precipitate of aluminium hydroxide \[Al{{\left( OH \right)}_{3}}\]. This reaction is a simple non redox reaction as there is no change in oxidation state of any of the species.

\[NaAl{{O}_{2}}+N{{H}_{4}}Cl+{{H}_{2}}O\to Al{{\left( OH \right)}_{3}}+NaCl+N{{H}_{3}}\]
Hence, the correct answer is the solution of meta aluminate on boiling with ammonium chloride gives a white precipitate of \[Al{{\left( OH \right)}_{3}}\]
So, the correct answer is “Option C”.

Note: Aluminium Hydroxide is an inorganic compound containing aluminium which is used in various immunologic preparations to improve immunogenicity, aluminium hydroxide adjuvant consists of aluminium hydroxide gel in a saline solution. It is a weak base as it can give hydroxide ions in an acidic solution.
Sodium aluminate is an inorganic chemical compound that is used as an effective source of aluminium hydroxide for many industrial and technical applications. Pure sodium aluminate (anhydrous) is a white crystalline solid. It generally exists in a hydrated form having 2 molecules of water.