Yasmin Jayathirtha
Last month, we saw spectacular examples of different kinds of reactions. Not all reactions are so colourful or exciting, but many are easy to do and helpful for students when writing out equations.
Chemistry textbooks give examples of reactions and also use the examples to explain the differences between physical and chemical changes, and mixtures and compounds.
The usual example uses iron powder and sulfur. Just mixed together, they can easily be separated and the books go on to state – ‘on heating the mixture, there is a glow and the compound iron sulfide is formed, the properties of which are very different from those of the mixture.’ This process appears very simple and most books have good illustrations. But, it is very difficult to get iron powder and sulfur to react. Iron powder gets rusted very easily and so nothing much happens and what is meant to be a very illustrative example just flops! What are the other examples that can be used?
The author works with Centre for Learning, Bengaluru. She can be reached at yasmin.cfl@gmail.com.