Which reaction is a decomposition reaction? A. 2KClO3 → 2KCl + 3O2 B. 4Na + O2 → 2Na2O C. ZnS + 3O2 → 2ZnO + 2SO2 D. 2NaBr + CaF2 → 2NaF + CaBr2

A. 2KClO₃ → 2KCl + 3O₂

Explanation:

In a decompostion reaction one single substances decomposes into two or more substances.

The general form for a decompostion reaction is: AB → A + B

In the reaction 2KClO₃ → 2KCl + 3O₂, the reactant, which is the compound shown on the left side of the reaction, i. e. KClO₃ will disappear and two new substances, the products, shown on the right side of the equation, will appear.

So, it is said that KClO₃ decomposes into KCl and O₂.