Mercury is the only metal which under normal conditions represents itself(himself) liquid. It is used in measuring devices, in vacuum pumps. Compounds of mercury apply as substances detonators and also in medical business and agriculture. Fluorescent lamps known to all shine thanks to mercury vapors too. This substance is still used in the hydrodynamic bearings which are exposed to especially heavy loading. How to find them in air?
Instruction
1. There is an easy and evident way based on high-quality reaction of mercury with copper iodide. The substance which is formed at the same time with a formula Cu2(HgI4) has rose-red color. The concentration of mercury, the, respectively, more intensive at it coloring is higher.
2. To manufacture the indicator, porous filter paper, any soluble salt of copper, for example, chloride, sulfate, potassium iodide salt solution, or sodium iodide and also solution of sulfite or hyposulphite of sodium is required.
3. Paper is cut by strips (the size is not basic, but for convenience it is better medium-sized), dipped in copper salt solution then it is taken, dry a little, and dip into iodine salt solution. The formed iodide copper will be mainly in a time of filter paper, and iodine – on a surface, because of it paper "will grow brown". Then strips place in solution of sulfite (hyposulphite) of sodium. Iodine is removed (it is visible on paper decolouration). Strips should be washed out in clear water, to dry. They are ready. It is desirable to store them in the dark place, in the closed capacity.
4. If there was a suspicion that at air there are mercury vapors, it is necessary to put on one strip in each checked room. In several hours, we check whether their color changed. If it became pinkish-red is an alarm signal. Means, in air there is a mercury! It is necessary to take measures for detection and removal of a source of this poison.