Question

Which of the following is a type of double decomposition reaction?
A) Neutralization reaction.
B) Precipitation reaction.
C) Electrolytic decomposition reaction.
D) All the above.

Answer 1

Hint:First, we understand the decomposition reaction.
If a compound breaks down into two or more substances then it is a decomposition reaction. The general equation for the reaction is,
$AB\stackrel{}{\to }A+B$

Complete step by step answer:

Now we see the double decomposition reaction.
The reaction in which the two reactants interchange their positive and negative ions and form a new compound is called a double decomposition reaction. The general equation of the reaction is,
$AB+CD\stackrel{}{\to }AD+CB$
Example:
On heating, ferrous sulfate crystals lose water and it forms anhydrous ferrous sulfate so the color of the crystal changes from light green to white, and on further heating anhydrous ferrous sulfate decomposes to give ferric oxide, sulfur dioxide, and sulfur trioxide.
$2FeS{O}_4\stackrel{\mathrm{\Delta }}{\to }F{e}_2{O}_3+S{O}_2+S{O}_3$
In the single reaction ferrous sulfate decomposed into three products thus it is a decomposition reaction.
Neutralization and precipitation reactions are double decomposition reactions.
Hence options A and B are correct.
Neutralization:
Neutralization may be a double decomposition reaction that occurs between the acids and bases.
Example:
The reaction between vinegar and bicarbonate of soda is an example of neutralization.
Precipitation reaction:
A precipitation reaction may be a double decomposition that occurs between two aqueous ionic compounds which form a replacement insoluble ionic compound.
Example:
The reaction between lead (II) nitrate and iodide is an example of a precipitation reaction.
Electrolytic decomposition is a type of decomposition reaction but it is not a double decomposition reaction.
Therefore, the option C is incorrect.

Additional Information:
Now we discuss the three types of decomposition reactions.
Thermal decomposition reaction: The decomposition reaction which is activated by the thermal energy is defined as a thermal decomposition reaction. The decomposition of Calcium Carbonate is a suitable example of a thermal decomposition reaction.
$CaC{O}_3\stackrel{\mathrm{\Delta }}{\to }CaO+C{O}_2$
Electrolytic decomposition reaction: The decomposition reaction which is activated by the electrical energy is defined as an electrolytic decomposition reaction. The electrolysis of water is a suitable example of an electrolytic decomposition reaction.
$2H_{2}O\stackrel{}{\to }2H_2+O_2$
Photolytic decomposition reaction: The decomposition reaction in reactants broken down to simpler substances by absorbing energy from photons is defined as a photolytic decomposition reaction. The decomposition of ozone is a suitable example of a photolytic decomposition reaction.
$O_3+h\gamma \stackrel{}{\to }{O}_2+O^{.}$

Note:
We must remember that the major application of decomposition reactions is the extraction of metals from their ores. For instance, zinc is often obtained from calamine by subjecting it to decomposition.