chemistry - the science of extremes.In the sense that the actual, real, describing the reality of it, or very small or very large.Very many people scared to number 23 zeros.It's really a lot.But many units (shares) is contained in one mole of a substance.Would you like to perform calculations with such huge numbers?It is not comfortable.But nowadays any student solves problems in chemistry by using a sheet of paper and a simple calculator.This is possible thanks to the special language of simplicity, created by chemists.And one of the key phrases of the language - "molecular mass".
formula to determine
Determine the molar mass is simple: the mass of matter should be divided by the number of its chemical.That is, you will know how much weight one mole of the substance.There is another way to determine the molar mass, but the main thing - do not get confused.The molar mass is numerically equal to the atomic or molecular weight.But the units are different.
In some situations, you may need the molar mass?A classic example - the need to reveal the formula of the substance.Not all substances and not all situations can be determined by chemical properties and appearance, it is sometimes necessary to consider the quantitative ratios.If you know the actual number of agents, one can calculate the form of atoms and their proportion in the substance.And you need the help of an old chemist.Really very old.Himself Mendeleyev.
The table will help us a great scientist?The molar mass of the substance is equal to the number of nuclear (atomic substances and for pure metals) or molecular weight, but it is measured in other units.This characteristic of the substance will appear on a grams per mole, the molecular - in atomic mass units.How is it that these same numbers?Those values that you see in the table for the elements were calculated empirically.Each species of atoms able to weigh and determine its mass in convenient units.Therefore, you can not minus twenty seventh degree, and quite decent numbers, often within units and hundreds.There are elements of the heavyweights, but in the school books of problems are usually not mentioned.
If not all the numbers at hand
What if a substance is composed of molecules and you know what that is?As searched the molar mass of the substance, if not its mass and chemical conditions on the number of concurrent tasks?It's simple, find every kind of atoms (elements) in the table of atomic weights and multiplies the number of atoms in the molecule for different elements.And then just add up - and get a molecular weight, which will be exactly the same as the mole.For today's young chemists everything is prepared - for the well-known formula to calculate the value of the desired material is no problem.
If you understand the essence of chemistry, it will seem very easy.The main burden during the development of this science - is to learn and remember the properties of specific substances, but the general processes and descriptions - simply nowhere.Once you realize potreniruetes - never in my life not to get confused.