A common characteristic of decomposition reactions is that they occur when a solid substance is heated.

1.  Calcium carbonate is strongly heated in a test tube.

• NOTE:  Carbonates generally decompose to form a metal oxide and carbon dioxide.

2.  A sample of magnesium carbonate is heated.

3.  Ammonia carbonate is heated.

4.  Sodium bicarbonate is heated.

5. Sodium chlorate is heated in the presence of a catalyst.

• NOTE:  The product NaCl does not dissociate into its ions (Na⁺ and Cl^-) because the reaction is not in solution.
• NOTE:  Generally, a chlorate decomposes to form a chloride salt and oxygen gas.

6. A sample of potassium chlorate is heated in the presence of manganese dioxide.

• NOTE:  Manganese dioxide is a catalyst in this reaction.  The presence of a catalyst is indicated by writing the name of the catalyst over the arrow.

7.  A sample of solid potassium nitrate is heated.

8.  Carbonic acid decomposes.

9.  A solution of hydrogen peroxide reacts in the presence of manganese dioxide.

• NOTE:  Manganese dioxide is a catalyst in this reaction.  The presence of a catalyst is indicated by writing the name of the catalyst over the arrow.

10.  Water is electrolyzed.

• NOTE:  The electrolysis is indicated by a "squiggle" mark above the arrow.

Next:  "Solubility Rules"