Hydrochloric acid which is also called chlorohydrogen contains in gastric juice and helps to digest proteinaceous food. In vitro it represents colourless caustic liquid which can be distinguished by means of rather simple and not demanding the special equipment high-quality reaction.
It is required to you
- Test tube with the checked substance, silver nitrate solution
Instruction
1. Hydrochloric acid, as well as any other acids, gives to the litmus indicator red color, interacts with metals and their oxides and also reacts others characteristic of acids. But to emit it from some other acids, it is necessary to carry out high-quality reaction to chloride ion.
2. Take a test tube in which presumably there is hydrochloric acid (HCl). Add a little solution of nitrate of silver (AgNO3) to this capacity. Act carefully and do not allow hit of reactants on skin. Nitrate of silver can leave black marks of which it will be possible to get rid only in several days on skin, and hit on skin of hydrochloric acid can cause the severe chemical burns.
3. You watch what will happen to the received solution. If color and consistence of contents of a test tube remain invariable, it will mean that substances did not react. In this case it will be possible to conclude with confidence that the checked substance was not hydrochloric acid.
4. If in a test tube there is a white deposit on consistences reminding cottage cheese or the turned milk it will demonstrate that substances reacted. Formation of chloride of silver (AgCl) became visible result of this reaction. Existence of this white curdled deposit will be the direct proof that originally in your test tube really there was hydrochloric, but not any other acid.
5. In the form of the equation this high-quality reaction will look as follows: HCl + AgNO3 = AgCl + HNO3. To emphasize that chloride of silver (AgCl) was formed in the form of a deposit, near a formula of this substance you will need to draw the arrow directed down.