- Amedo Avogardo proposed that the number of atoms in a 12.00000g of carbon be equal to a constant. (This is equal to 1 mol of carbon)
- This value is called Avogardo"s number and forms the basis of all quantitive chemistry
*1 mol = 6.02 x 10^23
- 1 mole is simply a multiple of things
- It represents a huge number of particles
Example
A sample of carbon contains 2.47x10^25 atoms. How many moles of carbon is this?
2.47 x 10^25 atoms x 1 mol/ 6.02 x 10^23 = 41.0 mol
12.5 moles of O2 represent how many molecules?
12.5 mol x 6.02 x 10^23/ 1 mol = 7.53 x 10^24
How many formula units are present in 0.57 mol of baCl2?
0.57 mol x 6.02 x 10^23/ 1 mol = 3.4 x 10^23 F.U.
