What type of reaction occurs when one compound reacts and is broken down into different elements or simpler compounds?

1 Answer
Feb 9, 2017

Explanation:

When a binary compound breaks down into separate elements OR when compounds break down into simpler compounds, it is known as a decomposition reaction.

The general formula for decomposition reactions are: AB -> A+B

Binary compounds:

HgO(s) -> Hg(l)+O_"2"(s)

2H_"2"O (l) -> 2H_"2" (s) + O_"2" (s)

2NaCl (s) -> 2Na (s) + Cl_"2" (g)

Simple compounds:

When a metal carbonate breaks down, it yields a metal oxide and carbon dioxide.

CaCO_"3" (s) -> CaO (s) + CO_"2" (g)

When a metal hydroxide breaks down, it yields a metal oxide and water. Acids work the same way, but no formation of a metal compound.

Mg(OH)_"2" (aq) -> MgO (s) + H_"2"O (l)

H_"3"PO_"4" (aq) -> P_"2"O_"5" (s) + H_"2"O (l)

When a chlorate breaks down, it yields a binary salt and oxygen gas.

KClO_"3" (s) -> KCl (s) + O_"2" (g)

Hope this helps :)