Mercury – a unique element, it is the metal which is under normal conditions in the liquid state! There are no such metals in all table of Mendeleyev any more. Vapors of mercury are extremely poisonous and lead to a serious poisoning therefore, it is very important to find their existence in air in time! Special insidiousness of this element that for the time being its negative impact is not shown in any way.
It is required to you
- - the filtered paper;
- - copper salt;
- - solution of iodide potassium.
Instruction
1. Take filter paper (better with a large time), any soluble salt of copper, for example, copper vitriol, solution of iodide potassium and solution of hyposulphite of sodium (it is sodium thiosulphate, it was widely used as a component of "fixer" in photographic business earlier).
2. Cut paper rectangular strips of the small size, for example, of 2х5 cm. Dip these strips in solution of copper vitriol. Then, having a little dried, dip them in solution of iodide potassium. Paper quickly will become brown.
3. After that rinse strips in sodium hyposulphite solution. Paper will become colourless. After washing in clear water and dehumidifications of a strip are ready to the use. They should be stored in the dark, densely closed capacity.
4. In what the meaning of the carried-out procedures? At first strips became impregnated with salt of the copper accumulating on all surface of paper (including, and in its time). Then, in interaction of copper vitriol with iodide potassium, new salt – iodide copper was formed, and pure iodine was emitted. Salt "concentrated" in a time, and iodine – on "smooth" sites of paper because of what it also accepted brown color. After washing by sodium thiosulphate solution, iodine was removed, and iodide copper remained in a time of strips. And from this point paper became mercury, "indicator", suitable for detection.
5. When it is necessary to check whether contain in air of couple of mercury, take out the prepared indicator strips from capacity and spread out indoors. Several hours later look whether paper accepted a pinkish-red shade. If accepted, so iodide copper reacted with mercury, having formed the complex Сu2(HgI4) connection, that is air is polluted by mercury vapors! Urgently take measures for removal of a source of pollution and disinfecting of the room.