Invisible inkwidely used for secret correspondence. To prepare invisible ink (disappearing ink) there are a few affordable ways that you can easily apply at home.
We need a solution of cobalt chloride CoCl2. Get it in a pen or syringe and make the inscription on the sheet of paper. Now let the letters dry.
The cobalt chloride - salt is pink in color, the inscription on the paper will not be visible. This salt is perfect for creating invisible ink. The writing appeared, it is necessary to heat, such as electric tile, within one minute. You can see that our letters will appear - beautiful blue.
In fact, that when heated, the molecules pink chloride cobalt lose some water, turning into a blue cobalt chloride.
You can easily make the label disappear again: it is enough to breathe on a sheet of paper with the inscription! (when the humidifying water is absorbed and the color is again pink and invisible on paper).
Invisible ink. Use copper sulphate
Invisible ink you can cook using a light solution of copper sulphate, which has a pale blue color. The chemical formula of copper sulphate CuSO4 x 5H2O.
Dissolve a little salt in the water, to the solution turned slightly blue. Leave this solution on paper.
The writing appeared, it is necessary to hold the sheet of paper over ammonia. After the manifestations of the invisible ink will be bright blue color, which is caused by the formation of beautiful color complex compounds of copper emmakate.
Invisible ink recipe Chinese Emperor
The Chinese Emperor used his secret label invisible ink of congee (rice water), which after drying did not leave any visible traces. But if this letter lightly moisten a weak alcoholic solution of iodine, then appear blue letters. Rice contains starch, and starch turns blue with the presence of iodine
Invisible ink. Use lemon juice
Pour a little citric acid and moisten the brush or wand. All, is possible to write something. After the inscription is done, let it dry. To show the label, it is necessary to heat the sheet of paper, for example over an electric light bulb or Ironing. Citric acid (or juice) darken when exposed to temperature and thus become visible
Invisible ink. Use iodine
Disappearing ink - such ink you can write, draw, but then the label disappears forever and it cannot be recovered!
Disappearing ink can be prepared, if you mix 50 ml of the alcoholic tincture of iodine with a teaspoon of dextrin (product of processing starch), and the precipitate filtered. Such ink completely lose color (disappear) after 1-2 days due to volatilisation of iodine
Disappearing ink "Iron letters"
Another recipe vanishing ink can be prepared with an aqueous solution of yellow blood salt K4[Fe(CN)6]. Written this solution letters disappear when the paper dries. And to see the inscription, it is necessary to moisten the paper with a solution of ferric chloride FeCl3. You can see bright blue letters, but they will not disappear. The appearance of the letters associated with the formation of complex compounds called tumbolia blue.