Chemical reactions call transformation of some substances possessing a certain structure and properties into other substances, with other structure and other properties. At this transformation no changes in structure of atomic kernels happen. In it the main difference of chemical reactions from those which occur in the nuclear reactor.
Instruction
1. Consider typical chemical reaction which is well familiar practically to any person. What occurs when make fire? Organic fuel (in this case, wood), to be exact - its main component, carbon – reacts oxidations with air oxygen. There is a chemical reaction which is followed by such plentiful allocation of heat that there is a flame. She registers thus: With + O2 = CO2 Or, for example, calcium oxide transformation (not extinguished lime) into calcium hydroxide (extinguished lime): SaO + H2O = Ca(OH)2
2. It is necessary to remember at once that, unlike the mathematical equations, in equations chemical reactions it is impossible to interchange the position of the left and right parts! The substances which are in the left member of equation chemical are called reagents, and being in the right part – reaction products.
3. Also it is necessary to write down correctly formulas of initial substances and products. After that make sure that such chemical reactions it is possible, that is its course does not contradict the known physical and chemical laws and rules. For example, reaction of AgNO3 + NaCl = NaNO3 + is possible AgCl, and the return reaction: AgNO3 do not have AgCl + NaNO3 = NaCl + - as chloride of silver is almost insoluble. And, in spite of the fact that formulas of substances are written correctly, such reaction is impracticable.
4. It is necessary to achieve that the amount of atoms of each element which was taking part in reaction in the left and right part was identical. It is the main indicator of correctness of the solution of the equation of chemical reaction. Example: how to solve the equation of such chemical reaction how restoration of iron hydrogen from oxide of iron trivalent? Write initial substances and products of reaction.Fe2O3 + to H2 = Fe + H2O
5. You at once see that the coefficient before a water formula in the right part of reaction has to be multiple 3 (as in the left part there are already three atoms of oxygen). Deliver this coefficient. At you it will turn out: Fe2O3 + H2 = Fe + 3H2O
6. By elementary selection you will find, as in left, and in the right member of equation has to be: 2 atoms of iron, 3 atoms of oxygen, 6 atoms of hydrogen, 3 atoms of oxygen. Means, final record of the equation of chemical reaction such: Fe2O3 + 3H2 = 2Fe + 3H2O