I’ve just replaced my laptop and was faced with the prospect of how to destroy the hard drive in my old laptop before taking it to the civic amenity site (rubbish dump) for recycling. Sadly this does seem a necessary thing to do these days to avoid the risk of identity theft. Rather surprisingly I found the almost ideal solution in a novel written by Sebastian Faulks. Faulks is well known for both his First World War novel ‘Birdsong’ and his Second World War novel ‘Charlotte Gray’. The current novel of his that I am reading is called ‘A week in December’ and is set in London in 2007. The book is published by Vintage Books, London and a good review written by Justin Cartwright  has appeared in the Guardian newspaper. It is not often that you find good chemistry described in a novel. Here is the relevant passage:

“He then took a hammer to the casing of his computer and extracted the hard disk. Rather to his surprise, it really was a disk, like a shiny CD and about the same size. In his father’s shed he mixed fine-powdered iron oxide and aluminium, both of which he had taken from the lab at college, poured them through a funnel into an empty drinks can, then stuck a magnesium strip in the top. He took this, along with the hard drive up on to the common at night, put the can on the disk, lit the magnesium strip and retreated. The drive was eliminated, as was the earth to a depth of more than a foot below it.”

This passage could be used to set a good data response question as what is described is, of course, the thermite reaction.

Fe₂O₃(s)  +  2Al(s)  →  2Fe(s)   +  Al₂O₃(s)

You could ask questions about why the iron is ‘fine-powdered’, what is oxidized and reduced and questions involving Hess’s law if you give them the two relevant half-equations:

2Al(s)   + 1½ O₂(g)  →  Al₂O₃(s)      ∆H = – 1676 kJ

2Fe(s)  +  1½ O₂(g)  →  Fe₂O₃(s)     ∆H = – 822 kJ

Assuming that most drinks cans are made of aluminium these days you could also ask them what happens to the can during the reaction and why a magnesium strip is used to start the reaction

All good chemistry with the added bonus that it is 100% certain to destroy completely all the data on your old hard drive.