AS Chemistry coursework november 17th 2003 Watch
I have been given the planning practical exercise and the objective is to measure the amount of magnesium carbonate that forms on the surface of the magnesium when left in air. Also formed on the surface is magnesium hydroxide and magnesium oxide. Does anybody know a complete reaction for the formation of all these products on the magnesium surface and how i could measure the amount of the magnesium carbonate that has formed on the surface. Thanks
I think they would occur separately and all depend on different factor, ie amount of water vapour in the air etc.
If you reacted all the magnesium with a strong acid (eg HCl) CO2 would be given off, as well as other gases-mostly O2. You could probably collect them all in a gas syringe. Not sure what you'd do next, the only methods I can think of merely give an indication of how much CO2 there is. Maybe take a sample from the gas syringe and dissolve it in water and test pH (CO2 would form a weak acid). Or mix a sample with lime water.
Hope this is of some use.