1. 4.5 – NOTES Moles

2. C.6 Introduction to the Mole Concept
Atoms and molecules are so tiny that it is not practical to measure them for laboratory purposes.
The Mole (mol) is also called Avogadro’s Number
It has a numerical value of 6.02 x 1023
1 mole of paperclips would circle the world 400 trillion times, and it would take 190 million centuries to finish it

3. The number of moles makes it easy to find the mass of things released during reactions
The mole can be thought of as the chemist’s dozen.
Formula mass is the sum of the masses of all the elements in a compound.

4. Molar mass Mass of exactly one mole of a substance
Used in the lab to relate moles of a substance to its mass
Found the same way as the formula mass.
The unit of measurement is the atomic mass unit, which is based on the mass of the carbon-12 atom. 1 amu = 1/12 the mass of a C-12 atom

5. To find the molar mass
Of an atom/ element: use average atomic mass from periodic table
Of a compound:
List elements in the compound.
Count # of atoms of each element.
Find atomic mass of each element.
Multiply # of atoms by atomic mass.
Add all masses together.

6. C.7 Molar Masses Find the molar mass of the following
Fluorine atoms, F
Fluorine molecules, F2

7. Potassium iodide, KI
Caffeine, C8H­10N4O2

8.  Magnesium Phosphate, Mg3(PO4)2