1. THE MOLE You should be able to:
Convert between molecular weight, number of atoms, number of moles, or mass
Determine % composition of an atom

2. What is a mole A mole is a counting unit like: 12 eggs = a dozen eggs
60 sec = a min
500 sheets of paper = ream

3. What is a mole 1 mole of Cu, Al, S, K2Cr2O7, H2O and CuCl2
Moles count particles
6.022 x 1023 particles = a mole (mol)
Called avagadro’s number (# atoms in 12 g 12C)
1 mol marbles would cover earth 50 mi deep!
1 mole of Cu, Al, S, K2Cr2O7, H2O and CuCl2

4. What is a mole
Uses
To count number of particles in a sample (from mass)
Since 12 g 12C = x 1023 atoms
12.01 g sample of natural carbon = x 1023 atoms (12C, 13C, and 14C)
Help use in determining outcome of reactions

5. practice
How many atoms of Ar = 7.5 mol ?
D.A. ?: 7.5 mol = ? Atoms Ar

6. practice How many mols are in 10.0 g of Al? D.A. ?: 10g Al= ? Mols Al
How many atoms?
D.A. ?: moles = ? Atoms

7. Molar mass A chemical compound = collection of atoms Ex CO2
Calculate the mass of 1 mol of CO2
Think about it: mass of 1 mol of CO2 = mass of 1 mol C + 2 mols of O
Mass of 1 mol of C = 12.01g and
Mass of 2 mols of O= 2 x g
Mass of 1 mol of CO2 = g + 2 (16.00 g)
=44.01 g = MOLAR MASS of CO2 (mass of 1 mole of CO2)

8. Molar Mass Calculate the molar mass of CH4
= 12.01g + 4(1.008 g) = g
Calculate how many moles are in 1.56 x 10-2 g of C10H6O3
Think about it
First need molar mass then do DA to solve
=8.96 x 10-5 mol C10H6O3

9. % composition Tells us % mass of an individual atom in a molecule
% comp.= mass of element in 1 mol of molecule x 100%
mass of 1 mol of molecule
% comp. of H in H2O
Mass of H= 2 mol (1.008 g) = g
Mass of 0= 1 mol (16.00 g) = g
Mass of 1 mol H2O = g g = g
% composition of H=mass of H in 1 mol of H2O x 100 %
mass of 1 mol of H2O
= 2.016g x 100 % = 11.2 %
18.016g