The chain of chemical transformations is the sequence of chemical reactions as a result of which some substances turn into others. To carry out such chain, it is necessary first of all to be able to write down correctly the equations of reactions and the nobility under what conditions they proceed. That is necessary minimum of knowledge: chemical properties of substances and ways of their receiving. Thus, for each "link" of a chain of chemical transformations pick up optimal conditions and, after all, receive final substance, having in the beginning only initial.
Instruction
1. For example, you are faced by a task: carry out the following chain of transformations: ethylene – ethane – chloroethane – ethyl alcohol.
2. Begin with the first link of a chain: ethylene – ethane. At first write their chemical formulas: C2H4 and C2H6. Ethylene is an unsaturated hydrocarbon (alkene) incorporating double communication, ethane is a saturated hydrocarbon (alkane). It differs from ethylene in availability of two additional atoms of hydrogen. Obviously in what way it is possible to turn one product into another, reaction takes place according to the following scheme: C2H4 + H2 = C2H6. Reaction goes at the increased temperature, pressure and also in the presence of the catalyst.
3. The second link of a chain: ethane – chloroethane. Again write their chemical formulas: C2H6 and C2H5Cl. Your task is to replace one atom of hydrogen in an ethane molecule with chlorine atom. How it can be done? Saturated hydrocarbons react with halogens under the influence of the UF-radiation promoting education of extremely active free radicals. They play a role of the initiator of reaction. It looks thus: C2H6 + Cl2 = C2H5Cl + HCl.
4. The third link of a chain – receiving ethyl alcohol from chloroethane. Their formulas, respectively: C2H5OH and C2H5Cl. That is you should replace chlorine atom in a chloroethane molecule with a hydroxyl group. How you can reach it? Influence chloroethane water solution of strong alkali. Reaction proceeds according to the following scheme: C2H5Cl + NaOH = C2H5OH + NaCl. As you can see, you achieved a goal, that is began with ethylene, came to ethyl alcohol.