Mole Concept Cheatsheet
Mole Concept Cheat Sheet
Atomic Mass Unit with Examples
Since atoms are too small particles we can not measure their weights with normal methods. Thus, scientist find another way to measure mass of atoms, molecules and compounds. They approve one atom of carbon isotopes 6C12 as 12 atomic mass unit. Mass of every elements expressed in terms of atomic mass unit is called relative atomic mass. We can also calculate relative molecule mass with same method; adding individual atomic masses of elements gives us relative molecular mass. For example;
1 H atom is 1 amu (amu=atomic mass unit)
1 H2O molecule includes 2 hydrogen atoms and one oxygen atom;
(2.1)+(16)=18 amu
The Mole Concept and Avogadro’s Number
A concept used for measure amount of particles like atoms, molecules. Number of atoms in the 6C12 element is equal to 1 mole. Number of particles in 1 mole is called Avogadro’s number; 6,02.1023.
1 mole atom contains 6,02x1023atoms
1 mole molecule contains 6,02x1023 molecules
1 mole ion contains 6,02x1023 ions
Mole=Number of Particles/Avogadro’s Number
Mass and Mole Relation:
1 mole N atom contains 14,01 g N
Mass of NO2is;
14,01+2.(16,00)=46,01 amu Thus;
1 mole NO2 is 46,01g NO2
1 mole N2 molecule is 2x14,01=28,02 g N2
Atom-gram, molecule-gram:
1 atom- gram Ca=1 mole Ca
1 molecule-gram CO2=1 mole CO2
Atomic Mass Unit, Gram Relation
1 O atom 16 amu
1 O atom 16/N g
where N is Avogadro’s number
Volume of Gases Mole Relation
Under same conditions ( temperature and pressure) gases contains same number of atoms and under same conditions mole and volume of gases are directly proportional to each other.
1 mole gas is 22,4 liter under standard conditions.