The pH value or rn represents itself the size characterizing a measure of activity of ions of hydrogen in any solution. It is very important to control constantly level rn waters if necessary to correct it to the values close to neutral size, for example, by means of ion-exchange pitches. How it can be done?
Instruction
1. The fastest and cheap, though not especially exact way is a definition of a pH value of water by means of special indicators. For this purpose it will be necessary for you: a sample of the studied water and also solutions of indicators of litmus and phenolphthalein in any net transparent tanks, for example, laboratory glass glasses.
2. Flow water in capacity with indicators and attentively track reaction, estimate the received solution: what its coloring. Remember that litmus in acidic environment accepts red color, and phenolphthalein in the alkaline environment – crimson. If addition of water does not lead to coloring change, then its pH value is close to neutral, that is to an indicator 7.
3. It is possible to use also special indicator strips. Apply a drop of the studied water on one of them, let's it be absorbed completely in paper and quickly compare the formed coloring to a reference scale.
4. More exact method is a method with use of rn-meters. These are special devices which principle of action is based on exact measurement of the electromotive force arising at immersion in the studied solution of two electrodes that is glass pH - an electrode and "a comparison electrode". For carrying out such measurement it is required only itself rn – meter and special capacity, for example, a glass glass into which the studied water is poured. Certainly, this capacity has to be clean (for an exception of the errors caused by pollution) and sufficient by the size that in it two electrodes freely were located.
5. Besides accuracy, rn – meters have that advantage that measurement of level of an indicator of water with their help can be organized in the continuous and automatic mode, without participation of the person that is very important for many large productions.