Descriptions of a number of the specific chemical reactions allowing to reveal any given connection are provided in a school course of chemistry. Many of them proceed with formation of the substances having colourful shades. Reaction by means of which it is possible to define sodium phosphate also concerns similar.
It is required to you
- - two test tubes;
- - the distilled water;
- - silver nitrate;
- - salt which is presumably sodium phosphate.
Instruction
1. Prepare everything, necessary for an experiment. On supports install two clean empty test tubes. They have to be rather wide. Prepare the container with the distilled water. It is desirable to pour it in a retort in advance.
2. Receive solution of the studied salt if it is in crystalline state. Pour a small amount the distilled water into one of test tubes. Then place in it a few crystals of the salt which is presumably sodium phosphate. Take a test tube from a support and begin liquid hashing, making it circular motions. Wait for full dissolution of crystals. If substance in a test tube is not dissolved - it is not phosphate of sodium. After the end of process of receiving solution install a test tube back on a support.
3. Prepare silver nitrate solution. Use a free test tube. Act with the way similar to that it was described in the previous step. Silver nitrate, as well as sodium phosphate, is very well soluble in water. Therefore solution of the necessary concentration will be received quickly enough.
4. Carry out reaction of determination of content of phosphate of sodium in solution of the studied salt. Carefully, a thin stream pour in liquid from the second test tube in the first. At the same time if the first test tube contains really sodium phosphate, in it the yellow deposit is almost instantly formed. It will be silver phosphate which is almost insoluble in water. The proceeding reaction can be described by the following equation: 3AgNO3 + Na3PO4 = 3NaNO3 + Ag3PO4.