Mercury – the only metal which is under normal conditions not in a firm look. Represents itself very dense, heavy liquid of dim silvery color. Vapors of mercury not only are very poisonous, but also are artful. As they have no smell, and the person who is exposed to their influence does not even guess danger. As to find them?
Instruction
1. The main method of receiving mercury – from its sulfide (cinnabar) by burning. Reaction proceeds thus: HgS + O2 = Hg + SO2 Being low-active metal, mercury hardly reacts. For example, to undergo oxidation by oxygen, it can only at high temperature (about 300 degrees).
2. There is very good and sensitive method available practically to everyone. The fact is that vapors of mercury react with copper iodide, forming at the same time the complex Сu2[HgI4] connection possessing depending on concentration, rose-red color of various intensity. It is possible to prepare quickly "indicator pieces of paper" by means of which check whether are present at air of couple of mercury.
3. For this purpose it is necessary to cut small rectangular pieces of filter paper and to dip them into solution of any salt of copper, for example, of chloride CuCl2 copper. To take out quickly, to dry and dip a little into solution of iodide potassium. At the same time there will be such reaction as potassium as more active metal, will force out copper from its salt: 2CuCl2 + 4KI = 2CuI + 4KCl + I2
4. As a result of reaction, iodide copper will fill a time of filter paper, and the emitted iodine "will paint" its surface. To remove iodine and to decolour paper, it is necessary to place it in sodium sulfite solution, it is possible to use hyposulphite solution, it is thiosulphate. After decolouration to wash out paper in clear water and to dry up. Indicator strips are ready for mercury. Store them in any closed ware.
5. For detection of vapors of mercury, it is necessary to leave strips on air within several hours. If they accepted a pinkish-reddish shade – it is necessary to look for urgently a pollution source mercury and to carry out all necessary measures to its neutralization and removal.