Tip 1: How to set up the equations of chemical reactions

main subject of study in chemistry is the reaction of the various chemical elements and compounds.A deep understanding of the laws governing the interaction of matter and processes in chemical reactions makes it possible to manage and exploit.Chemical Equation - a way to express a chemical reaction in which the starting materials of formula recorded and product ratios, indicating the number of molecules of each substance.Chemical reactions are divided into the reaction of the compound of substitution, decomposition and metabolism.Also among them are the redox, ionic, reversible and irreversible, exogenous etc.
Determine which substances interact with each other in your reaction.Write them on the left side of the equation.For example, consider the chemical reaction between aluminum and sulfuric acid.Position the reagents Left: Al + H2SO4

Then put the sign "equal", as in a mathematical equation.In chemistry, you can meet an arrow pointing to the right, or two opposing arrows, "a sign of

The interaction of the metal salt formed with an acid and hydrogen.The reaction products of record after the equal sign on the right.

Al + H2SO4 = Al2 (SO4) 3 + H2

result was a reaction scheme.
to make chemical equation, you need to find the coefficients.In the left part of the previously received part of the circuit consists of a sulfuric acid hydrogen atoms, sulfur and oxygen in a ratio of 2: 1: 4, the right side contains 3 sulfur atoms and oxygen atoms in 12 the salt and 2 hydrogen atoms per molecule of H2 gas.The left side of the ratio of these three elements is 2: 3: 12.
To equalize the amount of sulfur and oxygen atoms in the composition of aluminum sulfate (III), in place of the left-front acid ratio 3. Now the left part of the six hydrogen atoms.In order to equalize the number of elements hydrogen ratio of 3 to put him on the right side.Now the ratio of atoms on both sides of 2: 1: 6.
're equalize the amount of aluminum.Since the salt contains two metal atoms, 2 to set the coefficient of the aluminum in the left part of the circuit.

As a result, you get a reaction equation of the scheme.

2Al + 3H2SO4 = Al2 (SO4) 3 + 3H2

Tip 2: How to write reaction equation

reaction is called the transformation of some chemicals in the others.A formula of recording using special characters and the equation of the reaction.There are various types of chemical interactions, but the principle of recording of the formulas is identical.
How to create a reaction equation
you need
  • periodic system of chemical elements DIMendeleev
the left side of the equation is written starting materials that react.They are called reagents.Recording is performed using special symbols that denote each substance.Between substances reagents placed "plus" sign.
the right side of the equation is written formula obtained one or more substances, which are called the reaction products.Between the left and right sides of the equation instead of the equal sign is placed arrow that indicates the direction of reaction.
After the formulas of reactants and reaction products is necessary to place the coefficients of the reaction.This is done in order to, according to the law of conservation of mass, the number of atoms of the same element in the left and right sides of the equation remains the same.
To properly arrange the factors you need to consider each of the substances reactive.To this end one of the elements is taken and compared to the number of its atoms on the left and right.If it is different, then you need to find a multiple number indicating the number of atoms of the substance in the left and right sides.This is then divided by the number of atoms of the material in the corresponding portion of the equation, and the coefficient is obtained for each of its parts.
Since the coefficient placed before the formula and applies to all substances falling into it, the next step will be to compare the obtained data with the number of other substances, leading into the formula.This is done in the same way as with the first element, and taking into account the existing rate for the entire formula.
Once dismantled all the elements of the formula, final check compliance of the left and right sides.Then the equation of the reaction can be considered complete.
The equations of chemical reactions can not be reordered left and right sides.Otherwise, you get a completely different process diagram.
Helpful Hint
number of atoms as individual substances, reagents and materials included in the products of the reaction is determined by means of the periodic table of chemical elements DIMendeleev
  • reaction equation
Helpful Hint To check the job, you can use the law of conservation of mass.
  • how to balance chemical equation