Recognition of solution of nitrate of sodium happens step by step. At first we carry out reactions to existence of cations of sodium, and then - nitrite-anions. Only at necessary result of all reactions it is possible to claim that this solution - sodium nitrate solution.
It is required to you
- Solution of acetic acid, solution of zinc-uranil-acetate, diphenylamine solution, potassium permanganate solution, solution of sulfuric acid, torch, test tubes, pipettes.
1. Before carrying out the reactions necessary for definition in sodium nitrate solution, carefully we wash with the distilled water all test tubes which have to be colourless and the identical size. Then attentively we check expiration dates of all reactants which will be required to us.
2. There are two reactions for definition of cations of sodium. For carrying out the first it is poured in a test tube 1 ml of solution in which it is necessary to define sodium cations, we add several drops of solution of acetic acid, for a pridacha of acidic environment there. Then we add 0.5 ml of solution zinc-uranil-atseteta. Loss of a yellow crystal deposit shows on existence of cations of sodium. We check existence of a deposit, having leaned a test tube against a clean sheet of paper. For the following experience we take a torch, we set fire to its match and we drip test solution on a flame which has to be painted in yellow color. If both reactions yielded the necessary result, then we can claim that in solution there are sodium cations.
3. Further we pass to nitrate-anions. We carry out the first reaction: we add several drops of diphenylamine to 1 ml of solution, solution has to be painted in blue color. We take a clean sheet of paper and on its background we define color. The second reaction will require 2 ml of solution of permanganate of the potassium acidified by sulfuric acid which color can be from pink to a dark bardovogo depending on concentration. We add 1 ml of test solution to it – decolouration of permanganate of potassium should not happen. We do not forget about a clean sheet of paper against the background of which we will define color. This reaction is the main difference of nitrates from nitrites, nitrites decolour potassium permanganate solution. In the presence in solution nitrate-anions effects of these reactions will be such as it is described above.