Potassium chlorate, KClO3, decomposes to form potassium chloride, KCl and oxygen gas. How do you write a balanced equation for this decomposition reaction?

1 Answer
Dec 8, 2015

2KClO3(s) + heat2KCl(s)+3O2(g)

Explanation:

KClO3(s) + heatKCl(s)+O2(g)

Notice that the number of atoms of K and Cl are the same on both sides, but the numbers of O atoms are not. There are 3 O atoms on the the left side and 2 on the right. 3 and 2 are factors of 6, so add coefficients so that there are 6 O atoms on both sides.

2KClO3(s) + heatKCl(s)+3O2(g)

Now the KandCl atoms are not balanced. There are 2 of each on the left and 1 of each on the right. Add a coefficient of 2 in front of KCl.

2KClO3(s) + heat2KCl(s)+3O2(g)

The equation is now balanced with 2 K atoms, 2 Cl atoms, and 6 O atoms on both sides.