# How to determine the mass of a molecule ?

- handle
- Paper
- Periodic Table
- Calculator

interested person sometimes solve the most impossible tasks.People driven by a desire to know as much as possible, to penetrate into the depths of what seems unattainable at first glance.First it was the discovery of the laws of mechanics, then magnetism and electrostatics.The great breakthrough was the discovery of atoms and molecules.Until recently, a rather complicated, but solvable problem was how to determine the molecular weight.

These days it is no difficulty.The process of calculating the mass of any atom or molecule complex is carried out in several steps and is the same for any substance.The first step - the definition of the molecular weight of the substance.That is the invoice which atoms and how much each is found in the molecule.it should also be run if set such a task, how to calculate the mass of the gas.

Next, you need to resort to using the periodic table.In every cell there is a notation el

ement in Latin letters, its atomic number and atomic mass.The latter is often in some of the corners and consists of a number of three - four characters after the decimal point.In solving the problem, how to determine the weight of the solution should be calculated as an atomic mass of each of the components.further avoid misconceptions better to consider a specific example, namely to calculate the mass of a molecule of sulfuric acid H2SO4.There are two hydrogen atoms, a sulfur and four oxygen.The atomic mass of hydrogen is 1 atomic unit (au..), Sulphur - 32 as well.. Ie, oxygen - 16 as well.e. The total weight will be 2 * 1 + 32 + 64 = 98 a.e. This means that the molar mass of sulfuric acid is 98 grams per mole.The challenge is to find a relative molecular mass resolved, it remains to translate it into ordinary grams or kilograms.

further need Avogadro constant.This number is the number of structural units per mole of substance.The very constant approximately equal to 6.7 x 10 23 mol ^ (- 1).This means that 98 grams of sulfuric acid contains Avogadro's number of molecules.You're just something simply divide the mass of one mole of the number of molecules contained in it.In resolving the question of how to find the weight of the mixture, it should also be used Avogadrovu constant, because it is universal.

So, 98 / 6.7 * 10 ^ 23 = 6.7 * 10 ^ (- 23) grams.That is a number that represents zero, comma, another twenty-three zeros after the decimal point and then 6.7.This negligible mass shall, nevertheless, is the place to be.For a more accurate calculation can take full use of the periodic table, and more accurate computational resources than a calculator.