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Chocolate Chip Cookies 2.25 cups flour 8 Tbsp butter 0.5 cups shortening 0.75 cups sugar 0.75 cups brown sugar 1 tsp salt 1 tsp baking soda 1 tsp vanilla 0.5 cups Egg Beaters

Chocolate Chip Cookies 2.25 cups flour 8 Tbsp butter 0.5 cups shortening 0.75 cups sugar 0.75 cups brown sugar 1 tsp salt 1 tsp baking soda 1 tsp vanilla 0.5 cups Egg Beaters

How much?

What units?

Of what?

2.25 cups flour + 8 Tbsp butter + 0.5 cups shortening +

0.75 cups sugar + 0.75 cups brown sugar + 1 tsp salt +

1 tsp baking soda + 1 tsp vanilla + 0.5 cups Egg Beaters

(a synthesis reaction)

(177ºC)

1 batch of chocolate chip cookies!

coefficient

unit substance

• 2.25 cups flour• 8 Tbsp butter• 0.5 cups shortening• 0.75 cups sugar• 0.75 cups brown sugar• 1 tsp salt• 1 tsp baking soda• 1 tsp vanilla• 0.5 cups Egg Beaters

For 1 batch: The Egg Beaters I have are close to expiring! I’d like to use the rest of them in this recipe. I have 1.5 cups of Egg Beaters.

How many batches of cookies can I make with that many Egg Beaters?

Let’s Revisit the Cookies…

• 2.25 cups flour• 8 Tbsp butter• 0.5 cups shortening• 0.75 cups sugar• 0.75 cups brown sugar• 1 tsp salt• 1 tsp baking soda• 1 tsp vanilla• 0.5 cups Egg Beaters

For 1 batch: I have 1.5 cups of Egg Beaters.

How many batches of cookies can I make with that many Egg Beaters?

=

3.0 batches of cookies

1.5 cups E.B.

.5 cups E.B.

1 Batch

What is Stoichiometry? The study of quantitative relationships

within chemical reactions A balanced equation is the key to

stoichiometry! Tools you’ll need for this chapter:

Writing proper formulas and balanced reactions

Converting from mass to moles and vice versa

Determining the Mole-Ratio

Mole-Ratio Indicated by the coefficients in a balanced

equation

What is the mole-ratio between Mg and MgO?2 mol Mg

2 mol MgO

22 Mg + O Mg + O22 22 MgO MgO

Examples of Mole-Ratios

2KClO3 2KCl + 3O2

What is the mole-ratio of KClO3 and KCl?

2 moles KClO3

2 moles KClWhat is the mole-ratio of KClO3 and O2?

2 moles KClO3

3 moles O2

Another Example

Cu + 2AgNO3 2Ag + Cu(NO3)2

What is the mole ratio for silver nitrate and silver?2 moles AgNO3

2 moles Ag

What is the mole ratio for copper and silver nitrate? 1 mole of Cu

2 moles of AgNO3

Conversion Chart

Molar Mass(g/mol)

6.02 1023

particles/mol

MASSIN

GRAMSMOLES

NUMBEROF

PARTICLES

LITERSOF

SOLUTION

Molarity (mol/L)

The Mole-Mole Ratio is the core step!!

Stoichiometric Calculations

There are three types of stoichiometry problems we will deal with today:Mole-Mole problemsMass-Mole problemsMass-Mass problems

Step 1: Write a BALANCED EQUATION

Step 2: Determine known & unknowns

Step 3: Set up the mole ratio from the coefficients in the equation.

Step 4: Set up the problem like a unit conversion and solve!

Mole-Mole Problems

Mole-Mole ProblemsExample:

2 H2 + O2 2 H2O

How many moles of water can be formed from 0.5 mol H2?

= 0.5 mol H2O.5 mol H2

2 mol H2

2 mol H2O

Mole-Mole PracticeCuSO4 Al Al2(SO4)3 Cu3 2 3+ +

0.5 mol Al 3 mol CuSO4

2 mol Al= 0.75 mol CuSO4

Mole ratio

How many moles of CuSO4 are required to react with .5 moles of Al?

How many moles of Al2(SO4)3 are produced from .5 moles of Al?

0.5 mol Al 1 mol Al2(SO4)3

2 mol Al= .25 mol Al2(SO4)3

Mole ratio

Mole-Mole Practice

2.5 mol Ca 2 mol AlCl3

3 mol Ca= 1.7 mol AlCl3

2.5 mol Ca 3 mol CaCl2

3 mol Ca= 2.5 mol CaCl2

Ca AlCl3 CaCl2 Al3 2 2+ +3

How many moles of AlCl3 are required to react with 2.5 moles of Ca?

How many moles of CaCl2 are produced from 2.5 moles of Ca?

Mass-Mole Problems Step 1: Write a BALANCED EQUATION

Step 2: Determine your known & unknowns

Step 3: Convert known mass to moles (molar mass-known)

Step 4: Convert known mole to unknown mole (Mole-Mole ratio)

Mass-Mole ProblemsExample:

2 H2 + O22 H2O

How many moles of water can be formed from 48.0 g O2?

48.0 g O2

1 mol O2

2 mol H2O = 3.00 mol H2O

32.00 g O2

1 mol O2

Mass-Mole PracticeCuSO4 Al Al2(SO4)3 Cu3 2 3+ +

13.5 g Al 1 mol Al

26.98 g Al= 0.751 mol

CuSO4

13.5 g Al 1 mol Al2(SO4)3

2 mol Al= 0.250 mol

Al2(SO4)3

Mole ratio

3 mol CuSO4

2 mol Al

1 mol Al

26.98 g Al

How many moles of CuSO4 are required to react with 13.5 g of Al?

How many moles of Al2(SO4)3 are produced when 13.5g of Al react?

Mass-Mole Practice

5.7 g Ca 2 mol AlCl3

3 mol Ca= 0.095 mol AlCl3

5.7 g Ca 3 mol CaCl2

3 mol Ca= 0.14 mol CaCl2

Ca AlCl3 CaCl2 Al3 2 2+ +

1 mol Ca

40.08 g Ca

1 mol Ca

40.08 g Ca

3

How many moles of AlCl3 are required to react with 5.7g of Ca?

How many moles of CaCl2 are produced when 5.7g of Ca react?

Mass-Mass Problems Step 1: Write a BALANCED EQUATION

Step 2: Determine your known & unknowns

Step 3: Convert known mass to moles (molar mass-known)

Step 4: Convert known mole to unknown mole (Mole-Mole ratio)

Step 5: Convert unknown mole to gram (molar mass- unknown)

Mass-Mass ProblemsExample:

2 H2 + O22 H2O

How many grams of water can be formed from 48.0 g O2?

48.0 g O2

1 mol O2

2 mol H2O =32.00 g O2

1 mol O2 18.02 g H2O

1 mol H2O54.1 g H2O

Mass-Mass PracticeCuSO4 Al Al2(SO4)3 Cu3 2 3+ +

8.5 g Al 1 mol Al

26.98 g Al=

75 g CuSO4

8.5 g Al 1 mol Al2(SO4)3

2 mol Al=

54 g Al2(SO4)3

Mole ratio

3 mol CuSO4

2 mol Al

1 mol Al

26.98 g Al

1 mol CuSO4

342.14 g Al2(SO4)3

1 mol Al2(SO4)3

159.61 g CuSO4

How many grams of CuSO4 are required to react with 8.5g Al?

How many grams of Al2(SO4)3 are produced when 8.5g Al react?

Mass-Mass Practice

1.9 g Ca 2 mol AlCl3

3 mol Ca=

4.2 g AlCl3

1.9 g Ca 3 mol CaCl2

3 mol Ca=

5.3 g CaCl2

Ca AlCl3 CaCl2 Al3 2 2+ +

1 mol Ca

40.08 g Ca

1 mol Ca

40.08 g Ca

133.33 g AlCl3

1 mol AlCl3

1 mol CaCl2

110.98 g CaCl2

3

What mass of AlCl3 is required to react with 1.9g of Ca?

What mass of CaCl2 is produced when 1.9g of Ca react?