The main subject of study in chemistry are reactions between various chemical elements and substances. Deep understanding of regularities of interaction of substances and processes in chemical reactions gives the chance to operate them and to use in the purposes. The chemical equation is a way of expression of chemical reaction in which formulas of initial substances and products, coefficients showing quantity of molecules of each substance are written down. Chemical reactions are divided into reactions of connection, replacement, decomposition and exchange. Also it is possible to distinguish from them oxidation-reduction, ionic, reversible and irreversible, exogenous, etc.
Instruction
1. Define what substances interact with each other in your reaction. Write down them in the left member of equation. For an example, consider chemical reaction between aluminum and sulfuric acid. Arrange reagents at the left: Al+H2SO4Dalee put the sign "equally", as well as in the mathematical equation. In chemistry you can meet to the shooter, specifying to the right, or two opposite directed arrows, "the sign of reversibility". As a result of interaction of metal with acid salt and hydrogen are formed. Write down products of reaction after an equal-sign, on the right. Al+H2SO4=Al2(SO4) 3+N2Poluchilas scheme of reaction.
2. To work out the chemical equation, you need to find coefficients. In the left part of earlier received scheme atoms of hydrogen, sulfur and oxygen in the ratio 2:1:4 are a part of sulfuric acid, the right part contains 3 atoms of sulfur and 12 atoms of oxygen as a part of salt and 2 atoms of hydrogen in H2 gas molecule. The relation of these three elements is equal in the left part to 2:3:12.
3. To balance amount of atoms of sulfur and oxygen as a part of sulfate of aluminum (III), deliver in the left member of equation before acid coefficient 3. Now in the left part six atoms of hydrogen. To balance quantity of elements of hydrogen, deliver coefficient 3 before it in the right part. Now the ratio of atoms is equal in both parts to 2:1:6.
4. It was necessary to balance amount of aluminum. As as a part of salt two atoms of metal contain, deliver coefficient 2 before aluminum in the left part of the scheme. As a result you receive the equation of reaction of this scheme.2Al+3H2SO4=Al2 (SO4)3+3H2