All combustion reactions ... extremely exothermic chemical reactions. The first 'reaction' that we tried for our hand warmer involved dissolving potassium carbonate (K 2 CO 3) in water.

This is consolidated by using the thermal decomposition of calcium carbonate. Introduce the concept of conservation of mass in chemical reactions ... in relation to the combustion of hydrocarbons.

This is consolidated by using the thermal decomposition of calcium carbonate. Introduce the concept of conservation of mass in chemical reactions ... in relation to the combustion of hydrocarbons.