We saw last month that some reactions can be seen to happen, i.e. there is a precipitate, bubbles of gas are given off or some heat is generated. These were all reactions that occurred on just mixing the reagents together. There are many ways in which we can introduce reactions to students, and before going on to the more ordinary ones, I would like to share three spectacular reactions. Students look forward to chemistry for the bangs and colours and these are a good introduction to the wow factor in chemistry.
Rather dully, we can divide reactions into four types: Combination, displacement, decomposition and neutralisation. After doing these reactions, we can get them to classify and figure out equations and go on to the quieter ones.
Materials: Aluminium Fine Powder, Iron (III) Oxide [Ferric Oxide], Iodine crystals, Ammonium Dichromate, Sulfur powder, Magnesium ribbon.
All these are stable and can be stored for a long time. In fact, I have just finished the first sample of Ammonium Dichromate bought for the school twelve years ago.
The author works with Centre for Learning, Bengaluru. She can be reached at yasmin.cfl@gmail.com.