The structural formula is a graphic representation of the chemical structure of a molecule of substance in which the order of communication of atoms, their geometrical arrangement is shown. Besides, it demonstrates the valency of the atoms which are its part.
It is required to you
- - handle;
- - paper;
- - periodic system of elements.
Instruction
1. For the correct writing of a structural formula of any given chemical you have to know and represent well what is ability of atoms to form a certain number of electronic couples with other atoms. Valency will help you to draw chemical bonds. For example, the molecular formula of NH3 ammonia is given. You have to write a structural formula. Consider that hydrogen always odnovalenten therefore its atoms not can be are connected among themselves, therefore, they will are connected to nitrogen.
2. Correctly to write structural formulas of organic compounds, repeat basic provisions of the theory of A.M. Butlerov according to which there are isomers – substances with identical elementary structure, but with different chemical properties. For example, isobutane and butane. A molecular formula at them identical: C4H10, and structural – differ.
3. In a linear formula each atom registers separately therefore such image takes a lot of place. However by drawing up a structural formula, you can specify the total number of atoms of hydrogen at each atom of carbon. And between the next carbons draw chemical bonds in the form of lines.
4. Begin writing of isomers with hydrocarbon of the normal building, that is with an unbranched chain of carbon atoms. Then reduce by one atom of carbon which attach to other, internal carbon. Having exhausted all options of writing of isomers with this length of a chain, reduce it by one carbon atom. And again attach it to internal carbon atom of a chain. For example, structural formulas of N pentane, isopentane, tetramethylmethane. Thus, hydrocarbon with molecular formula C5H12 has three isomers.