Be careful when you do a demonstration
Tuesday 11 November 2014
The reaction of sodium with water is often demonstrated by a teacher as it is not recommended that students do the reaction for themselves. It would appear that this is the experiment being performed by an Egyptian teacher, Ahmed Gabr when it exploded in front of his class, although one British newspaper claims he was making oxyhydrogen (a mixture of hydrogen and oxygen). One of the students filmed the mishap and the video has gone viral. It raises several issues both about International-mindedness and Health and Safety. It is also a timely reminder that whenever you demonstrate something to a class of students you need to be well aware of all that could possibly go wrong and take precautions to avoid any accidents.
For those of us working in well-equipped schools it is easy to criticise the teacher for not using a safety screen, using glass apparatus that shatters in an explosion, and having students who are not wearing safety glasses much too close to the reaction. However in a school where money is tight and resources very limited maybe we should also give some credit (or at least show some empathy rather than just criticism) to a teacher who tries to make his chemistry lessons interesting by doing demonstrations instead of just showing yet another video of the reaction of alkali metals with water.
This incident was reported quite responsibly by the BBC who tried to look at the problems of trying to teach chemistry in a school with limited resources.
Contrast this with what was written in one of the British newspapers. “A chemistry teacher in Egypt has become a laughing stock after an explosive video of him bungling an experiment became a worldwide internet hit. The teacher was supposed to be showing the class how to produce a mild reaction by producing oxyhydrogen, or bang gas as it is also known. But he apparently bungled the quantities and sent children screaming from the classroom when the tumbler he was using exploded, showering the room with sparks, flying glass and boiling chemicals.”