1. Chemical Reactions Unit
Stoichiometry

2. - the study of the quantitative aspects of chemical reactions.
STOICHIOMETRY
- the study of the quantitative aspects of chemical reactions.

3. The Mole
6.02 X 1023

4. A Mole of Particles 1 Mole= 6.02 x 1023 particles
= x 1023 C atoms
= x 1023 H2O molecules
= x 1023 NaCl molecules
1 mole C
1 mole H2O
1 mole NaCl

5. Molar Mass The Mass of 1 mole (in grams)
Equal to the atomic mass (get from periodic table)
1 mole of C atoms = g
1 mole of Mg atoms = g
1 mole of Cu atoms = g

6. Everything must go through Moles!!!
Calculations
molar mass Avogadro’s number Grams Moles particles
Everything must go through Moles!!!

7. Mole Ratios
A mole ratio converts moles of one compound in a balanced chemical equation into moles of another compound.

8. Molar Ratios
N2 + 3H2  2NH3

9. N2 + 3H2  2NH3
How many moles of hydrogen (H2) would I need to produce as moles of ammonia (NH3)?

10. Calculating Masses of Reactants and Products
Balance the equation.
Convert masses to moles.
Set up mole ratios.
Use mole ratios to calculate moles of desired molecule.
Convert moles to grams or to particles, if necessary.

11. Working a Stoichiometry Problem
6.50 grams of aluminum reacts with an excess of oxygen. How many grams of aluminum oxide are formed?
4 Al O2  2Al2O3
6.50 g Al
1 mol Al
2 mol Al2O3
g Al2O3 =
? g Al2O3
26.98 g Al
4 mol Al
1 mol Al2O3
6.50 x 2 x ÷ ÷ 4 =
12.3 g Al2O3

12. Percent Yield