What is the amount of matter and how is it determined?

Let's talk about what a quantity of substance,as the term is used in the subjects of the natural science cycle. Since quantitative relations in chemistry and physics are given serious attention, it is important to know the physical meaning of all quantities, their units of measurement, and the scope of application.

Designation, definition, units of measure

In chemistry, quantitativerelations. Special calculations are used to calculate the equations. In order to understand what is the amount of matter in chemistry, we will give the term definition. This is a physical quantity that characterizes the number of analogous structural units (atoms, ions, molecules, electrons) present in matter. To understand what the amount of matter is, we note that this quantity has its own designation. When performing calculations that imply the use of this quantity, use the letter n. The units of measurement are mole, kmol, mmol.

Value of the value

Eighth graders who do not yet know how to writechemical equations, do not know what the amount of matter is, how to use this value in calculations. After getting acquainted with the law of constancy of the mass of substances, the significance of this quantity becomes clear. For example, in the reaction of burning hydrogen in oxygen, the ratio of reactants is two to one. If the mass of hydrogen entering the process is known, it is possible to determine the amount of oxygen that took part in the chemical reaction.

Application of formulas to the amount of substanceallows you to reduce the ratio between the initial reagents, simplify the calculation. What is the amount of matter in chemistry? From the point of view of mathematical calculations, these are the stereochemical coefficients set in the equation. They are used to carry out certain calculations. The way to calculate the number of molecules is inconvenient, it is the Mole that is used. Using Avogadro's number, it can be calculated that 1 mole of any reagent includes 6 · 1023 moles^-1.

Calculations

Do you want to understand what is the amount of matter? In physics, this quantity is also used. It is needed in molecular physics, where calculations are made of the pressure and volume of gaseous substances according to the Mendeleev-Clapeyron equation. To carry out any quantitative calculations, the concept of molar mass is applied.

Under it mean the mass thatcorresponds to one mole of a particular chemical. Determine the molar mass through the relative atomic masses (their sum taking into account the number of atoms in the molecule) or to determine through a known mass of matter, its amount (mole).

No task of the school chemistry course related tocalculations by the equation, is not complete without the use of such a term as the "amount of substance". Owning the algorithm, you can cope not only with the usual software calculations, but also with complex olympiad tasks. In addition to calculations through the mass of matter, it is also possible, with the help of this concept, to perform calculations through a molar volume. This is important in cases when gaseous substances take part in the interaction.