Question

State an important use of decomposition reactions.

Answer 1

Hint: In this reaction, a reactant breaks down to give two or more simpler products. There is only one reactant in this reaction.

Complete step by step answer:
The type of chemical reaction in which under specific conditions, one simple compound breaks down to give two or more simpler compounds is called decomposition reaction. The general mechanism of a decomposition reaction is:
\[A - B \to A + B\]
Decomposition reactions are the opposite of combination reactions. combination reaction is a chemical reaction in which two or more substances combine together to produce a new compound. A decomposition reaction can be both endothermic and exothermic, though the latter is more predominant. For instance, decomposition of NO to \[{N_2}\,and\,{O_2}\] is exothermic while decomposition of ozone (\[{O_3}\]) to atmospheric oxygen (\[{O_2}\]) is exothermic.
Some of the important uses of decomposition reactions are:
Extraction of metals from its constituent ores: Many metals like zinc can be extracted from their respective ores by the method of decomposition. Zinc is extracted from its carbonate ore Calamine (\[ZnC{O_3}\]). The chemical reaction of the same is:

\[ZnC{O_{3(s)}} \to Zn{O_{(s)}} + C{O_{2(g)}}\]

Electrolysis of molten Aluminium oxide to form aluminium: In the industrial process for the manufacturing of aluminium, electricity is passed through molten aluminium (III) oxide to obtain aluminium and oxygen.
\[2A{l_2}{O_3} \to 4Al + 3{O_2}\]

To obtain Sodium metal from sodium chloride: Sodium can be obtained by the electrolysis of molten sodium chloride.
\[2NaC{l_{(l)}} \to 2N{a_{(s)}} + C{l_{2(g)}}\]

Note: Do not confuse decomposition reactions with double decomposition reactions. A double decomposition reaction is a type of decomposition reaction in which two constituent reactants interchange positive and negative ions and form two new compounds.