Chloric iron (chemical formula FeCl3) represents crystals of black-brown color with different shades depending on impurity: from red to violet. Substance extremely hygroscopic, quickly absorbs moisture from air, turning into FeCl3x6H2O hexahydrate – crystals of yellow color.
Instruction
1. Receive this substance or by impact of gaseous chlorine on iron shavings (it is better – sawdust): 2Fe + 3Cl2 = 2FeCl3Libo by oxidation of chloride iron chlorine: 2FeCl2 + Cl2 = 2FeCl3
2. When using as "protravitel", has essential advantage before the concentrated nitric acid: during etching poisonous nitrogen oxides are not formed, first of all, the well-known "fox tail" there are NO2! However it is not so simple to dissolve waterless chloric iron.
3. Often, especially, when using in amateur practice, it or in general is dissolved hardly, or at dissolution forms a fine suspension which very much prevents work. Because of it there are defects of etching – "not pickle". How to cope with this problem? It is correct to dissolve!
4. It is necessary to use no more than 1 part of chloric iron on 3 parts of water (on weight). Water has to be hotter. By itself, cleaner, ideally – distilled. Capacity has to be glass or ceramic (as a last resort, from the plastic maintaining high temperature).
5. Add chloric iron to hot water in the small portions, at intensive hashing. Many inexperienced fans arrive on the contrary: pour water into the lump of chloric iron, and are perplexed: why some nonsense turns out! Process of dissolution is followed by rough gas generation, and at these gases there is a poisonous chlorine therefore everything is better to do under draft, as a last resort – in the open air.
6. After the last portion is dissolved, it is necessary to wait at least several hours (better – day). During this time the deposit which separates filtering will drop out. Solution of chloric iron - transparent dark brown liquid - it is possible to store almost unlimited term in net plastic capacity.
7. In some cases, if dissolution goes with great difficulty, it is possible to try "to acidify" solution, having added about 10% (from the total weight of chloric iron) hydrochloric acid. As a rule, it helps.