Bell RingerAluminum + Sulfuric Acid Aluminum Sulfate + Hydrogen Gas

Which of the following is the balanced chemical equation for the reaction shown above?

A Al + H2SO4 Al2(SO4)3 + H2B 2Al + 3H2SO4 Al2(SO4)3 + 3H2C 2Al + 3H2SO4 Al2(SO4)3 + H2

D 2Al + H2SO4 Al2(SO4)3 + H2 2004 SOL

Nerf & Poof Factor MethodCONVERSION FACTORS:

1 nerf = 3 poof 5 splunk = 6 mews

2 poof = 7 splat 2 pock = 3 splunk

4 trad = 1 pock 8 splat = 3 trad

1. 6 nerf = ? trad

2. 3.6 mews = ? pock

3. 7 poof = ? nerf

4. 3 mol Na2P = ?atoms Na

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?

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

How much?

Of what?

Chocolate Chip Cookies• 2.25 cups • 8 Tbsp• 0.5 cups • 0.75 cups • 0.75 cups• 1 tsp • 1 tsp• 1 tsp• 0.5 cups

How much?

What units?

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?

Get on with it!

What does this have to do with CHEMISTRY?

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

Welcome to STOICHIOMETRY

Mr. Trotts

2008

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

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: 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?

1.5 cups E.B. x1 batch cookies

0.5 cups E.B.=

3.0 batches of cookies

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 much butter do I need to deplete (use up) the Egg Beaters?

1.5 cups E.B. x8 Tbsp butter

0.5 cups E.B.=

24 Tablespoons of butter

… Back to Chemistry• There are three types of stoichiometry

problems we will deal with today:– Mole-Mole problems (1 conversion)– Mass-Mole problems (2 conversions)– Mass-Mass problems (3 conversions)

given required

• Step 1: Write a BALANCED EQUATION

• Step 2: Determine the mole ratio from the coefficients in the equation.– Mole ratio = moles of required substance

moles of given substance

• Step 3: Set up the problem like a unit conversion and solve!

Baby Steps… Mole-Mole Problems

Mole-Mole ProblemsExample:

2 H2 + O22 H2O

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

0.5 mol H2 x2 mol H2

2 mol H2O = 0.5 mol H2O

Mole-Mole Practice

CuSO4 Al Al2(SO4)3 Cu3 2 3+ +

1. a. 0.5 mol Al 3 mol CuSO4

2 mol Al=x 0.8 mol CuSO4

b.

c.

0.5 mol Al 1 mol Al2(SO4)3

2 mol Al=x 0.3 mol Al2(SO4)3

0.5 mol Al 3 mol Cu

2 mol Al=x 0.8 mol Cu

Mole ratio

0.5 mol? mol ? mol ? mol

#2) Ca + AlCl3 CaCl2 + Al

1. Balance the formula

2. Given 2.5 moles Ca find the number of moles of AlCl3, CaCl2, and Al needed.

Mole-Mole Practice

2. a. 2.5 mol Ca 2 mol AlCl3

3 mol Ca=x 1.7 mol AlCl3

b.

c.

2.5 mol Ca 3 mol CaCl2

3 mol Ca=x 2.5 mol CaCl2

2.5 mol Ca 2 mol Al

3 mol Ca=x 1.7 mol Al

Ca AlCl3 CaCl2 Al3 2 2+ +3

• complete the mole to mole worksheet Do not write on the handout!!

Quiz: mole to mole

• 5 moles of Ca(OH)2 is added to a container of HCl in an attempt to neutralize the acid. How many moles of the HCl will be neutralized as CaCl2 and water are produced? Show your work for credit to include the molar ratio.

Mass-Mole Problems

• Step 1: Write a BALANCED EQUATION

• Step 2: Calculate the molar mass of your given substance and convert from mass to moles

• Step 3: Determine the mole ratio from the coefficients in the equation

• Step 4: Set up the conversion and solve!

Mass-Mole ProblemsExample:

2 H2 + O22 H2O

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

48.0 g O2 x1 mol O2

2 mol H2O = 3.00 mol H2O

32.00 g O2

1 mol O2 x

Mass-Mole Practice

CuSO4 Al Al2(SO4)3 Cu3 2 3+ +

3a. 13.5 g Al 1 mol Al

26.98 g Al=x 0.751 mol

CuSO4

b.

c.

13.5 g Al 1 mol Al2(SO4)3

2 mol Al=x 0.250 mol

Al2(SO4)3

13.5 g Al 3 mol Cu

2 mol Al=x 0.751 mol

Cu

Mole ratio

x3 mol CuSO4

2 mol Al

1 mol Al

26.98 g Alx

1 mol Al

26.98 g Alx

13.5 g? mol ? mol ? mol

#4 Ca + AlCl3 CaCl2 + Al

1. Balance the equation

2. Given 5.7 g of Calcium find the number of moles of AlCl3, CaCl2, and Al

Mass-Mole Practice

4. a. 5.7 g Ca 2 mol AlCl3

3 mol Ca=x 0.095 mol AlCl3

b.

c.

5.7 g Ca 3 mol CaCl2

3 mol Ca=x 0.14 mol CaCl2

5.7 g Ca 2 mol Al

3 mol Ca=x 0.095 mol Al

Ca AlCl3 CaCl2 Al3 2 2+ +

1 mol Ca x

x

x

40.08 g Ca

1 mol Ca

40.08 g Ca

1 mol Ca

40.08 g Ca

3

Mass-Mass Problems

Example:

2 H2 + O22 H2O

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

48.0 g O2 x1 mol O2

2 mol H2O =32.00 g O2

1 mol O2 x x18.02 g H2O

1 mol H2O54.1 g H2O

Mass-Mass Practice

CuSO4 Al Al2(SO4)3 Cu3 2 3+ +

5. a. 8.5 g Al 1 mol Al

26.98 g Al=x

75 g CuSO4

b. 8.5 g Al 1 mol Al2(SO4)3

2 mol Al=x

54 g Al2(SO4)3

Mole ratio

x3 mol CuSO4

2 mol Al

1 mol Al

26.98 g Alx

1 mol CuSO4

342.14 g Al2(SO4)3

1 mol Al2(SO4)3

x

x

159.61 g CuSO4

8.5 g? g ? g ? g

Mass-Mass Practicec. 8.5 g Al 3 mol Cu

2 mol Al=x

30. g Cu

1 mol Al

26.98 g Alx x 63.55 g Cu

1 mol Cu

#6a. How many grams of aluminum chloride would be required to completely react with 1.9 grams of Calcium?

#6b. How many grams of Calcium chloride will be produced from 1.9 grams of Calcium?

#6c. How many grams of Aluminum will be produced from 1.9 grams of Calcium?

Mass-Mass Practice

6. a. 1.9 g Ca 2 mol AlCl3

3 mol Ca=x

4.2 g AlCl3

b. 1.9 g Ca 3 mol CaCl2

3 mol Ca=x

5.3 g CaCl2

Ca AlCl3 CaCl2 Al3 2 2+ +

1 mol Ca x

x

40.08 g Ca

1 mol Ca

40.08 g Ca

x 133.33 g AlCl3

1 mol AlCl3

x1 mol CaCl2

110.98 g CaCl2

3

Mass-Mass Practice

c. 1.9 g Ca 2 mol Al

3 mol Ca=x

0.85 g Al

x1 mol Ca

40.08 g Ca 1 mol Al

26.98 g Alx

Ca AlCl3 CaCl2 Al3 2 2+ +3

• Now complete the Mass to Mass handout Do not write on the handout

Quiz

7. 7.5 moles of potassium phosphate is reacted with excess barium chloride. How many grams of potassium chloride are produced in the reaction?

Write a balanced equation

Use the equation and molar ratios to solve the problem