Each element is able to form a simplesubstance, being in a free state. In this state, the motion of atoms is the same, they are symmetrical. In complex substances, the situation is much more complicated. Chemical bonds are asymmetric in this case, complex covalent bonds are formed in the molecules of complex substances.
What is meant by oxidation
There are such compounds in which the electrons are distributed most unevenly, i.e. when complex substances are formed, the valence electrons pass from atom to atom.
It is this uneven distribution incomplex substances is called oxidation or oxidation. The charge of an atom formed in this molecule is called the degree of oxidation of the elements. Depending on the nature of the transition of electrons from atom to atom, a negative or positive degree is distinguished. In the case of recoil or the acceptance by the atom of an element of several electrons, respectively, the positive and negative degrees of oxidation of the chemical elements (E + or E
-). For example, the K
+1 means that the potassium atom gave up one electron.In any organic compound, the central place is occupied by carbon atoms. The valence of this element corresponds to the 4th in any compound, however, in different compounds the degree of oxidation of carbon will be different, it will be -2, +2, ± 4. Such a nature of different values of valence and degree of oxidation is observed in practically any compound.
Determination of oxidation state
To correctly determine the degree of oxidation, you need to know the underlying postulates.
Metals are not capable of having a minus degree,However, there are rare exceptions when a metal forms compounds with a metal. In the periodic system, the number of the atom group corresponds to the maximum possible degree of oxidation: carbon, oxygen, hydrogen and any other element. The electronegative atom, when displaced towards one another by an electron, receives a charge of -1, two electrons -2, and so on. This rule does not apply to the same atoms. For example, for the H-H bond, it will be 0. The C-H = -1 bond. The degree of oxidation of carbon in the C-O bond is + 2. The metals of the first and second groups of the Mendeleyev system and fluorine (-1) have the same degree value. In hydrogen, this degree is practically in all compounds equal to +1, except for hydrides in which it is -1. For elements that have a non-constant degree, it can be calculated by knowing the connection formula. The basic rule that states that the sum of powers in any molecule is 0.
Example of calculating the degree of oxidation
Consider the calculation of the degree of oxidation by the example of carbon in the compound CH3CL. Let's take the initial data:the degree of hydrogen is +1, and that of chlorine -1. For convenience, in the calculation of x we will assume the degree of oxidation of carbon. Then, for CH3CL there will be an equation x + 3 * (+ 1) + (- 1) = 0. Performing simple arithmetic actions, it can be determined that the degree of oxidation of carbon will be equal to +2. In this way, calculations can be made for any element in a compound.
