The Mole

Say What? Ewww who would want to learn about those big brown things.

NO! This is chem class.

Okay this guy is Avogadro. This guy basically invented the mole.
One of the most important things to note is his hypothesis and it is named after him

Avogadro's Hypothesis
Equal volumes of different gases at the same temperature and pressure have the same number of particles

Enough with this charming looking dude.

You are still wondering what a mole is right? Right, because I have not told you yet.
The Mole allows chemistst to count atoms and molecules.

Avaogadro's Number

Yes children, the mole has a number. And this number is just 1 mole

Sorry but i cannot tell you how big it is. It is big. Very Big.

Back to Avogadro's hypothesis if there are the same number of particles in atom , the mass ratio is due to the mass of the particles. (used for the relative masses of all atoms on the periodic table.)

The mass of 1 atom of the element is counted in atomic mass units or amu.

Eg. Fluorine = 19.0 amu (because its atomic mass is 19)

When you want to find the mass of an ionic compound, you use the formula mass.

E.g. Potassium(K)+Fluoride(F)

         39.1            +   19.0 amu       =     58.1 amu

For covalent compounds, you use the Molecular mass.

E.g. Carbon Dioxide

          C        O2

           12 +   16.0x2

C02 = 44.0 amu

For pure substances, you use the atomic/molecular/formula mass in grams per mole)

Ex. 1 mole of oxygen is 16.0g/mol

Here is a song that we had in chem class talks about moles. Its fun.


But if you really want to learn about moles, watch this.