Copper – widespread metal which one of the first was mastered by the person. For a long time, in view of the relative softness, copper was used mainly in the form of bronze – alloy with tin. It meets both in nuggets, and in the form of connections. Represents plastic metal of golden-pinkish color, on air quickly becomes covered by the oxide film giving to copper a yellow-red shade. How to define whether copper contains in any given product?
Instruction
1. To find copper, it is possible to carry out quite simple high-quality reaction. For this purpose plane a metal piece on shaving. If you want to analyze a wire, it needs to be cut small pieces.
2. Then pour in a test tube of a little concentrated nitric acid. Carefully lower shaving or pieces of a wire there. Reaction begins practically at once, and it demands big accuracy and care. It is good if there is an opportunity to perform this operation in an exhaust case or, as a last resort, in the fresh air as poisonous oxides nitrogen, very unhealthy are allocated. It is easy to see them as they have brown color — the so-called "fox tail" turns out.
3. The formed solution needs to be evaporated on a torch. It is also very desirable to do it in an exhaust case. At this moment not only safe water vapor, but also acid vapors, and the remained nitrogen oxides are removed. Completely it is not necessary to evaporate solution.
4. In the same solution pour several drops of ammonia. It is necessary to do it by means of the pipette. If in nitric acid you dissolved a copper wire or sawdust, solution will be painted in bright blue color.