Stoichiometry - Chemical equations are the recipes that tell the manufacturer how much of each chemical to use in making a product. - Stoichiometry is.

StoichiometryStoichiometry- Chemical equations are the recipes that Chemical equations are the recipes that

tell the manufacturer how much of each tell the manufacturer how much of each chemical to use in making a product.chemical to use in making a product.

- StoichiometryStoichiometry is the calculation of is the calculation of quantities in chemical reactions.quantities in chemical reactions.

- Stoichiometric calculationsStoichiometric calculations are are calculations done using calculations done using balancedbalanced chemical equations.chemical equations.

Proportional RelationshipsProportional Relationships

2 1/4 c. flour1 tsp. baking soda1 tsp. salt1 c. butter3/4 c. sugar

3/4 c. brown sugar1 tsp vanilla extract2 eggs2 c. chocolate chipsMakes 5 dozen cookies.

I have 5 eggs. How many cookies I have 5 eggs. How many cookies can I make?can I make?

5 eggs 5 doz.

2 eggs= 12.5 dozen cookies

Ratio of eggs to cookies

2 cups mix + 2 egg + 0.25 cup oil + 1 cup milk → 8 pancakes

How many cups of mix will you need to make 24 pancakes?

How many cups of oil will you need to make 28 pancakes?

How many pancakes can you make with 13 cups of mix?

Proportional RelationshipsProportional Relationships

N2 + H2 NH323

What does this equation tell us?What does this equation tell us?

Interpreting Chemical ReactionsInterpreting Chemical Reactions

Proportional Relationships in Proportional Relationships in EquationsEquations

NN22 + 3H + 3H22 → 2NH → 2NH33

What is the relationship between NWhat is the relationship between N22 and H and H22??

What is the relationship between NWhat is the relationship between N22 and NH and NH33??

What is the relationship between HWhat is the relationship between H22 and NH and NH33??

Interpreting Chemical EquationsInterpreting Chemical Equations

Lets describe this reaction in terms of the Lets describe this reaction in terms of the number of particles.number of particles.

2H2H22 ++ O O22 →→ 2H 2H22OO

2 molecules H2 + 1 molecule O2→ 2 molecules H2O

Interpreting Chemical EquationsInterpreting Chemical Equations

Lets describe this reaction in terms of the Lets describe this reaction in terms of the number of moles.number of moles.

2H2H22 ++ O O22 →→ 2H 2H22OO

2 moles H2 + 1 moles O2 → 2 moles H2O

Interpreting Chemical EquationsInterpreting Chemical Equations

Lets describe this reaction in terms of mass.Lets describe this reaction in terms of mass.

2H2H22 ++ O O22 →→ 2H 2H22OO

4.0316 g H2 + 31.998 g O2 → 36.0296 g H2O

2 mol H2 x 2.0158 g 1 mol

1 mol O2 x 31.998 g 1 mol

2 mol H2Ox 18.0148 g 1 mol

Stoichiometry StepsStoichiometry Steps

1.1. Write a balanced equation.Write a balanced equation.2.2. Identify known & unknown.Identify known & unknown.3.3. Line up conversion factors.Line up conversion factors.

a.a. Mole ratio (moles to moles) is the core Mole ratio (moles to moles) is the core step in all stoichiometry problems.step in all stoichiometry problems.

How many moles of ammonia (NHHow many moles of ammonia (NH33) are ) are

produced when 0.60 moles Nitrogen reacts with produced when 0.60 moles Nitrogen reacts with Hydrogen?Hydrogen?

Mole to Mole CalculationsMole to Mole Calculations

First you need the balanced equation.N2 + 3H2 → 2NH3

Now according to the equation:

When 1 mole of nitrogen reacts with hydrogen, 2 mole of ammonia are produced.

Conversion Factor: 1 mol N2 = 2 mol NH3

0.60 mol N2 x1 mol N2

2 mol NH3 = 1.2 mol NH3

How many moles of hydrogen are needed to How many moles of hydrogen are needed to produce 2.3 moles of ammonia (NHproduce 2.3 moles of ammonia (NH33)?)?

Mole to Mole CalculationsMole to Mole Calculations

N2 + 3H2 → 2NH3

Now according to the equation:

When 3 mole of hydrogen reacts with nitrogen, 2 mole of ammonia are produced.

Conversion Factor: 2 mol NH3 = 3 mol H2

2.3 mol NH3 x2 mol NH3

3 mol H2 = 3.45 mol H2

How many grams of hydrogen are needed to How many grams of hydrogen are needed to react with 23.2 grams nitrogen?react with 23.2 grams nitrogen?

Mass to Mass CalculationsMass to Mass Calculations

N2 + 3H2 → 2NH3

Now according to the equation:

3 moles of hydrogen are required for every 1 mole of nitrogen.Conversion Factor: 1 mol N2 = 3 mol H2

23.2 g N2 x

28.014 g N2

1 mol N2= 5.01 g H2x

3 mol H2

1 mol N2

x1 mol H2

2.0158 g H2

How many liters of hydrogen are needed to How many liters of hydrogen are needed to react with 54.3 liters of nitrogen?react with 54.3 liters of nitrogen?

Volume to Volume CalculationsVolume to Volume Calculations

N2 + 3H2 → 2NH3

Now according to the equation:

3 moles of hydrogen are required for every 1 mole of nitrogen.Conversion Factor: 1 mol N2 = 3 mol H2

54.3 L N2 x22.4 L N2

1 mol N2= 162.9 L H2x

3 mol H2

1 mol N2

x1 mol H2

22.4 L H2

How many grams of hydrogen are needed to How many grams of hydrogen are needed to react with 54.3 liters of nitrogen?react with 54.3 liters of nitrogen?

Mass to Volume CalculationsMass to Volume Calculations

N2 + 3H2 → 2NH3

Now according to the equation:

3 moles of hydrogen are required for every 1 mole of nitrogen.Conversion Factor: 1 mol N2 = 3 mol H2

54.3 L N2x22.4 L N2

1 mol N2= 14.66 g H2

x3 mol H2

1 mol N2

x1 mol H2

2.0158 g H2

How many grams of hydrogen are needed to react with 54.3 liters of nitrogen?

54.3 L N2 x

22.4 L N2

1 mol N2= 14.66 g H2

x3 mol H2

1 mol N2

x

1 mol H2

2.0158 g H2

How many liters of hydrogen are needed to react with 54.3 liters of nitrogen?

54.3 L N2 x22.4 L N2

1 mol N2 = 162.9 L H2x3 mol H2

1 mol N2

x1 mol H2

22.4 L H2

Difference between the last 2 equations Difference between the last 2 equations

- The Stoichiometry Map is the same as the Mole Map with 1 step added in the middle.

Stoichiometry MapStoichiometry Map