Iron – one of the most important minerals necessary for normal functioning of a human body. Its shortcoming can lead to serious diseases. Nevertheless, the surplus is also harmful. As soluble compounds of iron often are in drinking water, it is very important to be able to define this chemical element and to calculate its concentration.
It is required to you
- - potassium permanganate;
- - set of the aquarian;
- - liquid ammonia;
- - solution of sulphosalicylic acid.
Instruction
1. Water in which there is a big impurity of compounds of iron has characteristic ferruterous smack. If to leave it in glasswares for several days, at a bottom and walls the yellowish-brown film is formed.
2. Add weak (light pink) permanganatepotassium KMnO4 solution to water. If it contains a significant amount of soluble compounds of iron, light pink color of solution of permanganate of potassium either will disappear at all, or will change on yellowish-brown. The more in iron water, the this color will be more dark. Certainly, it is very inexact, rough ways of definition of iron. With their help it is possible to answer a question only: whether there are connections of this element in water.
3. You can acquire the so-called set of the aquarian of domestic or import production which is specially created for determination of content of iron in water in pet-shops. The operation manual is attached to each set. Following it, you calculate concentration of iron. Of course, these data will be very approximate.
4. If you need high precision, can use high-quality reaction with sulphosalicylic acid. It is based that ions of bivalent and trivalent iron in the alkaline environment react with sulphosalicylic acid, forming complex connection with steady yellow color. Judging by intensity of this yellow coloring, define the general concentration of iron by photometric methods of the analysis.
5. Analysis course: take sample of the studied water (25 milliliters), add to it 1 milliliter of 10% liquid ammonia and 1 milliliter of 20% solution of sulphosalicylic acid. Mix, wait 15 minutes. Then carry out the photometric analysis with the light filter calculated on wavelength in the range of 400–430 nanometers. As standards of comparison it is recommended to use water solutions of zhelezoammoniyny alum.