In this demonstration experiment, a small conical heap of orange ammonium dichromate VI is ignited and starts to decompose exothermically. The reaction resembles a volcanic eruption, producing sparks, a large volume of green chromium lll oxide ‘ash’, steam and nitrogen gas.
This demonstration experiment can be used to show chemical change, since the products are dramatically different from the starting material. The reaction is a striking example of an exothermic decomposition reaction. The energy given out heats up the products, and steam and sparks are also produced.
The demonstration itself lasts about 2 minutes, but more time is needed for discussion and explanation before and after the demonstration.