Post on 03-Jan-2016
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Stoichiometry
Mole Map
Mole Island
Particle Peninsula
Mass Mountain
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
Proportional Relationships
I have 5 eggs. How many cookies can I make?
3/4 c. brown sugar1 tsp vanilla extract2 eggs2 c. chocolate chipsMakes 5 dozen cookies.
2 1/4 c. flour1 tsp. baking soda1 tsp. salt1 c. butter3/4 c. sugar
5 eggs 5 doz.
2 eggs= 12.5 dozen cookies
Ratio of eggs to cookies
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
150 cookies
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.
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 1 mole O2
MOLE RATIOFrom the balanced equation.
Coefficients tell moles of each substance.
Mole Island
Stoichiometry Sea Known UnknownSubstance A Substance B
Mass Mountain
Particle Peninsula
Mole Island
Mass Mountain
Particle Peninsula
Mole RatioRaft
1 mole = 6.022 x 10 23 particles
(atoms or molecules)
Mass
Particles
Mole Mole
Mass
Particles
Known
Substance A1 mole = molar mass (g)
Use coefficientsfrom balanced
chemical equation
1 mole =
6.022 x
1023 partic
les
(atoms o
r molecu
les)
1 mole =
molar m
ass (g
)
Unknown
Substance B
Stoichiometry Steps1. Write a balanced equation.2. Identify known & unknown.3. Line up conversion factors.
– Mole ratio - moles moles– Molar mass - moles grams
Core step in all stoichiometry problems!!
– Mole ratio - moles moles
4. Check answer.
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
How many moles of KClO3 must decompose in order to produce 9 moles of oxygen gas?
2KClO3 2KCl + 3O2 ? mol 9 mol
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
O2 KClO3
x mol KClO3 = 9 mol O2 = 6 mol KClO3
2 mol KClO3
3 mol O26 mol
Stoichiometry
2 TiO2 + 4 Cl2 + 3 C CO2 + 2 CO + 2 TiCl4
4.55 molx mol
C Cl2
x mol Cl2 = 4.55 mol C3 mol C
= 6.07 mol Cl24 mol Cl2
C TiO2
x molecules TiCl4 = 115 g TiO2 80 g TiO2
= 8.66x1023 molecules TiCl4
1 mol TiO2 2 mol TiCl42 mol TiO2
6.02x1023 molecules TiCl41 mol TiCl4
x g TiO2 = 4.55 mol C3 mol C
= 243 g TiO2
2 mol TiO2 80 g TiO2
1 mol TiO2
How many moles of chlorine will react with 4.55 moles of carbon?
How many grams of titanium (IV) oxide will react with 4.55 moles of carbon?
x g
How many molecules of TiCl4 will react with 115 g TiO2?
TiO2 TiCl4
x molecules115 g