Stoichiometry, Percent Yield, Unit 7 Review

Week 26 Chemistry

Warm Up: 5 Minutes

You should be working SILENTLY

Stay in your own seat

Calculate the number of moles of NH3 produced by the reaction of 6.2 grams of hydrogen with an excess of nitrogen.

N2 + 3 H2 2 NH3

 

Write the Learning Target

Agenda

Warm Up [7 minutes] Notes/Examples [15 minutes] Guided Practice [12 minutes] Independent Practice [17 minutes] Closing [2 Minutes]

Today’s Stoichiometric focus

Mass to Mass

Mass X Mole X Mole Y Mass Y

Example 1

Calculate the number of grams of NH3 produced by the reaction of 5.40g of hydrogen with an excess of nitrogen. The balanced equation is

N2 + 3 H2 2 NH3

Acetylene gas (C2H2) is produced by adding water to calcium carbide (CaC2). How many grams of acetylene are produced by adding water to 5.00 grams CaC2?

CaC2 + 2 H2O C2H2 + Ca(OH)2

Example 2

Guided Practice

Teacher:

1. Will show the problem on the board Students:

1. Take 27 seconds to read the problem and write your given and unknown

2. Take 88 seconds to solve the problem with your shoulder partner

3. Be ready to share when Mr. Ghosh says SWAG

Guided Practice #1

The combustion of acetylene follows the reaction shown below:

2 C2H2 + 5 O2 4 CO2 + 2 H2O

If 52.00 grams of C2H2 are burned, how many grams of oxygen are required?

159.8 grams O2

Guided Practice #2

Lithium nitride reacts with water to form ammonia and lithium hydroxide:

Li3N + 3 H2O NH3 + 3 LiOH

What mass of water is required to react with 32.9 grams of Li3N?

51.1 grams H2O

Independent Practice

Take some time to practice some mass to mass stoichiometry

Practice makes Perfect

85%

Closing

What steps would you take to perform a mass to mass stoichiometry problem?

Warm Up: 5 Minutes

You should be working SILENTLY

Stay in your own seat

Calculate the number of grams of oxygen required to react with 11.4 grams of magnesium.

2 Mg + O2 2 MgO 

Write the Learning Target

Hint: Use your flowchart

Agenda

Warm Up [7 minutes] Notes/Examples [15 minutes] Guided Practice [12 minutes] Independent Practice [17 minutes] Closing [2 Minutes]

Today’s Stoichiometric focus

Mole to Volume

Mole X Mole Y Volume Y

Volume to Mole

Volume Y Mole Y Mole X

When Converting from Mole to Volume…

Reaction has to take place at

so you can use the following relationship…

22.4 L = 1 Mole

STP (Standard Temperature and Pressure)!!!

Example 1

Determine the volume of chlorine gas needed react with calcium to produce 5.4 moles of calcium chloride at STP.

Ca + Cl2 CaCl2

Example 2

The combustion of acetylene follows the reaction shown below:

2 C2H2 + 5 O2 4 CO2 + 2 H2O

Determine the number of moles of C2H2 that reacted if 13L of carbon dioxide were produced at STP.

Guided Practice

Teacher:

1. Will show the problem on the board Students:

1. Take 27 seconds to read the problem and write your given and unknown

2. Take 78 seconds to solve the problem with your shoulder partner

3. Be ready to share when Mr. Ghosh says SWAG

Guided Practice #1

Assuming STP, how many liters of oxygen are needed to produce 4.2 moles of sulfur trioxide?

2 SO2 + O2 → 2 SO3

47 Liters O2

Guided Practice #2

The following reaction is carried out at STP:

2 C4H10 + 13 O2 8 CO2 + 10 H2O

How many moles of C4H10 reacted if 24.6L of carbon dioxide were produced?

0.275 moles C4H10

Independent Practice

Take some time to practice some mole to volume stoichiometry

Practice makes Perfect

85%

Closing

Describe the process used to solve mole to volume stoichiometry problems

Wednesday at G/T Training…

Warm Up: 4 Minutes

You should be working SILENTLY

Stay in your own seat

What volume of hydrogen gas is produced when 2.96 moles of zinc react?

___Zn + ___HCl ___ZnCl2 + ___H2

 

Write the Learning Target

Agenda

Warm Up [7 minutes] Flipped Classroom Video [6 minutes] Notes/Examples [12 minutes] Guided Practice [12 minutes] Independent Practice [14 minutes] Closing [2 Minutes]

The Flipped Classroom

Thoughts/Questions?

I’m planning on trying this starting with our next unit

Vocabulary Words for Today

Theoretical Yield:

Actual Yield:

Percent Yield:

How much should be formed

How much is actually formed

% Yield=Actual Yield

TheoreticalYieldx100%

Example 1

Use the equation below to answer the following question:

8 Fe + S8 8 FeS

The theoretical yield of FeS is 29.4 grams. If 21.7 grams of FeS are produced from the reaction, what is the percent yield of FeS?

Example 2

In an experiment, 17.7 grams of water are formed from the reaction of 1.96 moles of hydrobromic acid. If the theoretical yield is 35.3 grams, what is the percent yield of water, to the nearest tenth of a percent?

HBr + NaOH NaBr + H2O

Guided Practice

Teacher:

1. Will show the problem on the board Students:

1. Take 17 seconds to read the problem and write your given and unknown

2. Take 48 seconds to solve the problem with your shoulder partner

3. Be ready to share when Mr. Ghosh says SWAG

Guided Practice #1

Use the equation below to answer the following question:

2 FePO4 + 3 Na2SO4 Fe2(SO4)3 + 2 Na3PO4

The theoretical yield of iron (III) sulfate is 33 grams. If 18.5 grams of iron (III) sulfate are produced from the reaction, what is the percent yield of iron (III) sulfate?

56%

Guided Practice #2

In an experiment, 366.7 grams of sodium sulfite are formed from the reaction of 1.322 moles of aluminum sulfite. If the theoretical yield is 499.9 grams, what is the percent yield of sodium sulfite, to the nearest tenth of a percent?

Al2(SO3)3 + 6 NaOH 3 Na2SO3 + 2 Al(OH)3

73.4%

Independent Practice

Take some time to practice some percent yield problems

Practice makes Perfect

85%

Closing

Describe the process for finding percent yield

Warm Up: 3 Minutes

You should be working SILENTLY

Stay in your own seat

In an experiment, 61.5 grams of iron (III) chloride are formed when 0.712 moles of hydrochloric acid reacts. If the theoretical yield is 120.1 grams, what is the percentage yield of iron (III) chloride, to the nearest tenth of a percent?

5 HIO3 + 4 FeI2 + 25 HCl 4 FeCl3 + 13 ICl + 15 H2O 

Write the Learning Target

Agenda

Warm Up: 5 Minutes Expectations for Stations: 3 minutes Stations Review: 36 minutes Closing: 1 Minute

How Will Stations Work??

You will be placed with a group of other scholars to complete five stations on the following topics:

Station 1: Mole to Mole Stoichiometry

Station 2: Mole to Volume Stoichiometry

Station 3: Mole to Mass Stoichiometry

Station 4: Mass to Mole Stoichiometry

Station 5: Mass to Mass Stoichiometry

You Need: •Periodic Table•Flowchart

How Will Stations Work??

You will spend 7 minutes at each station working each problem as a group on scratch paper.

You will write your FINAL answer on the answer document.

When time is called, you will leave your current station and move on to the next station

You will have 10 seconds to move to the next station

Closing

Why did we review these concepts? Why is it important that everybody master

these objectives?

Good Luck on Your Exam