1. Stoichiometry The Mole - Study Questions
1.       What were Avogadro’s 2 major contributions to chemistry?
2.       What is the unit for mass used on the periodic table?
3.       How does molecular mass differ from molar mass?
4.       Convert 200 g of FeO to moles.
5.       Convert 3 mol of CO2 to grams.
6.       What is a conversion factor?
7.       If 25 g of a substance equals 1 mole, what conversion factor would you use to convert 1.5 mol to grams?
8.       What conversion factor would be used to convert 3 mol of the substance in question 10 to grams?
9.       What is the unit used for molecular and formula mass?
10.     What is the unit of molar mass?
11.     The oxidation of 50.0 g of Mn produces 79.1 g of an oxide. Calculate (a) the percent composition, and (b) the empirical formula of this oxide.
12.     What two things are conserved in a chemical reaction?
13.     Why aren’t moles conserved in a chemical reaction?
For the next 4 questions balance the equation and calculate the indicated quantity.
14.       K(s) + H2O (g)  KOH(aq) + H2(g) How much KOH will be produced from 100 g of K?
15.       Fe2O3(s) + C  Fe(l) + CO(g) How much CO will be produced from 100 g of C?
16.       CaC2(s) + H2O(l)  Ca(OH)2(s) + CsH2(g) How much CaC2 is required to produce 100 g of C2H2?
17.       C4H10(g) + O2  CO2(g) + H2O(l) How much H2O can be produced using 100 g O2?
18.     What is a mole?
19.     How many particles are there in a mole?

2. Mole Map
Mass Mountain
Liter Lake
Mole Island
Particle Peninsula

3. Using the Mole Map with Chemical Equations
We can convert between Moles, Particles and Grams, but…
This only gives us information about one substance!
How do we determine how much reactants to use in a chemical reaction? Or how much product we will create?
STOICHIOMETRY

4. Proportional Relationships
2 1/4 c. flour
1 tsp. baking soda
1 tsp. salt
1 c. butter
3/4 c. sugar
3/4 c. brown sugar
1 tsp vanilla extract
2 eggs
2 c. chocolate chips
Makes 5 dozen cookies.
I have 5 eggs. How many cookies can I make?
Ratio of eggs to cookies
5 eggs
5 doz.
2 eggs
= 12.5 dozen cookies
150 cookies
Courtesy Christy Johannesson

5. Mole Ratio
A conversion factor that converts moles of one compound in a balanced chemical equation into moles of another compound.
2 H2 + O2  2 H2O
Coefficients tell how many particles (or MOLES of particles) of each chemical is needed in the reaction.

6. Mole Ratios
How many moles of water will be formed if I react 14.0 moles of oxygen with excess H2?
2 H2 + O2  2 H2O
14.0 moles O2 x 2 moles H2O = 28.0 moles H2O mole O2
MOLE RATIO
From the balanced equation.
Coefficients tell moles of each substance.

7. Stoichiometry Sea Known Unknown Substance A Substance B Mole Ratio
Mass Mountain
Mass Mountain
Liter Lake
Liter Lake
Mole Ratio
Raft
Mole Island
Mole Island
Particle Peninsula
Particle Peninsula

8. Known Substance A Unknown Substance B Mass Mass
1 mole = molar mass (g)
1 mole = molar mass (g)
Mole
Volume
Use coefficients
from balanced
chemical equation
Mole
1 mole = STP
1 mole = STP
Volume
1 mole = x 1023 particles
(atoms or molecules)
1 mole = x 1023 particles
(atoms or molecules)
Particles
Particles

9. Stoichiometry Steps Core step in all stoichiometry problems!!
1. Write a balanced equation.
2. Identify known & unknown.
3. Line up conversion factors.
Mole ratio - moles  moles
Molar mass - moles  grams
Mole ratio - moles  moles
4. Check answer.
Core step in all stoichiometry problems!!
Courtesy Christy Johannesson

10. How many moles of KClO3 must decompose in order to produce 9 moles of oxygen gas?
2KClO3  2KCl O2
? mol
9 mol
2 mol KClO3
x mol KClO3 = 9 mol O2
6 mol
= 6 mol KClO3
3 mol O2 O2
KClO3
Courtesy Christy Johannesson

11. Stoichiometry 2 TiO2 + 4 Cl2 + 3 C CO2 + 2 CO + 2 TiCl4
115 g
x g
x mol
4.55 mol
x molecules
How many moles of chlorine will react with 4.55 moles of carbon?
4 mol Cl2
x mol Cl2 = mol C
= mol Cl2
3 mol C C
Cl2
How many grams of titanium (IV) oxide will react with 4.55 moles of carbon?
2 mol TiO2
80 g TiO2
x g TiO2 = mol C
= 243 g TiO2
3 mol C
1 mol TiO2 C
TiO2
How many molecules of TiCl4 will react with 115 g TiO2?
1 mol TiO2
2 mol TiCl4
6.02x1023 molecules TiCl4
x molecules TiCl4 = 115 g TiO2
80 g TiO2
2 mol TiO2
1 mol TiCl4
= 8.66x1023 molecules TiCl4
TiO2
TiCl4