1. Ch. 8 Stoichiometry

2. Title and Highlight Right Side – NOTES ONLY TN Ch 8.1 Date Topic: EQ:
Book Questions:
Write Question out (left side of red line) and answer it (Highlight answer) based on from what you read.
Notes:
Write out the notes from my website.
You may use different color pens.
Use Bullets or Number notes.
Space out your notes so you can add any additional into during lecture.
NO HIGHLIGTING, UNDERLINING, etc
WE WILL DO OUR FOCUS NOTES TOGETHER
Summary:
Write 2-3 sentences (end of notes) from what you learned from reading, notes, and/or lecture.

3. Title and Highlight
LEFT Side – PICTURES, PRACTICE PROBLEMS, ETC
TN Ch 8.1
DRAW ANY PICTURES, FIGURES, AND WRITE OUT ANY PRACTICE PROBLEMS/QUESTIONS.
WE WILL ANSWER THEM TOGETHER. LEAVE SPACES SO WE CAN ANSWER QUES.

4. Ch. 8.1-8.3 Topic: Stoichiometry
EQ: What is a mole ratio and how is it used in conversions?
READ Ch (pg )
Write Questions & Answer Questions #1, 2a, 3 (notes side) Highlight answer

5. Stoichiometry refers to the numerical relationship between chemical quantities in a balanced chemical equation.

6. What are the “mole ratios” in this equation?
Interpreting Chemical Equations
The first thing that must be done is to ______________ the equation!
___N2 (g) + ___H2 (g)  ___NH3 (g)
What are the “mole ratios” in this equation?
Here are the kinds of information you can get from the equation:
____ mole N ____ moles H2  ____ moles NH3
____ molecules N ____ molecules H2  ____ molecules NH3
balance 1 3 2
MOLE
RATIOS!! 1 3 2 2 1 3

7. Stoichiometry Conversion Chart
Don’t draw – you already have a copy
Stoichiometry Conversion Chart
Mass A
Mass B
Molar
Mass
Molar
Mass
Avogadro’s #
Avogadro’s #
Particles A
Mole A
Mole
Ratio
Mole B
Particles B
Count
them
Count
them
Count
them
Molar Volume
Molar Volume
Count
them
mole a
mole b
Atoms/Ions in A
Volume A
Volume
Ratio
Volume B
Atoms/Ions in B

8. Mole to Mole Conversions
The conversion factor is the mole ratio.
The mole ratio comes from the _________________ of the balanced chemical equation.
Step 1: Write down the known (A) and unknown (B).
Step 2: Set up a mole ratio to change from moles A to moles B
coefficients

9. Practice Problems: N2 (g) + 3H2 (g)  2NH3 (g)
Left side - Leave about 5 spaces between each problem
Practice Problems: N2 (g) H2 (g)  2NH3 (g)
How many moles of ammonia can be made from 7 moles of nitrogen reacting with an excess of hydrogen?
How many moles of hydrogen are required to completely react with 8 moles of nitrogen to produce ammonia?
How many moles of hydrogen are needed to react with an excess of nitrogen to make 10 moles of ammonia?

10. Ch. 8.4 Topic: Mole to Mass Conversion
EQ: How are mole ratios used in mole-mass conversions?
READ Ch 8.4 (pg )
Write Questions & Answer Questions #4 (notes side) Highlight answer

11. Practice Problem: CaH2 (s) + 2H2O (l)  Ca(OH)2 (aq)+ 2H2 (g)
Left side - Leave about 5 spaces between each problem
Practice Problem: CaH2 (s) H2O (l)  Ca(OH)2 (aq)+ 2H2 (g)
What mass of calcium hydroxide will be produced from the reaction of 2.50 mol of calcium hydride with excess water? (another product is hydrogen gas)
2. What mass of water is needed?

12. Mass-Mass Conversion Problems
Mass-Mass: (mass A to moles A to moles B to mass B)
Step 1: Write down the known (A) and unknown (B).
Step 2: Convert from mass A to moles A
Step 3: Convert from moles A to moles B using a mole ratio.
Step 4: Convert from moles B to mass B.

13. Left side - Leave about 5 spaces between each problem
Practice Problem:
3. How many grams of ammonia can be made from reacting 39.0 grams of nitrogen with an excess of hydrogen?
N2 (g) H2 (g)  2NH3 (g)

14. Ch. 8.5 Topic: Limiting and Excess Reactants
EQ: What is the difference between L.R. and E.R.?
***BONUS QUESTION ON EXAM***
READ Ch 8.5 (pg )
Write Questions & Answer Questions #7 (notes side) Highlight answer

15. Limiting Reagent (or Limiting Reactant)
The limiting reagent is a REACTANT that _________ _____ first.
Once the limiting reagent runs out, the rxn stops!!
The reactant that is in abundance (reactant that you have too much of) is called the ___________ reagent.
runs out
excess

16. To summarize:
• Limiting reactant (or limiting reagent)—the reactant that is completely consumed in a chemical reaction.
You run out of this reactant first and it stops the rxn.
Once you determine LR, that chemical starts every calculation especially THEORETICAL YIELD of product
• Excess Reactant— the reactant you have too much of and have leftovers not being used in the rxn.

17. Practice Problem #1 2Na(s) + Cl2(g)  2 NaCl(s)
Left side - Leave about 10 spaces between each problem
Practice Problem #1
2Na(s) + Cl2(g)  2 NaCl(s)
Know: 53.2 g Na and 65.8 g Cl2 Find: limiting reactant & theoretical yield of NaCl

18. Cu2O(s) + C(s)  2 Cu(s) + CO(g)
Left side - Leave about 10 spaces between each problem
Practice Problem #2
Cu2O(s) + C(s)  2 Cu(s) + CO(g)
Given: 11.5 g Cu2O and g C Find: limiting reactant & theoretical yield of Cu

19. Ch. 8.6 Topic: Percent Yield
EQ: How do you calculate % yield from actual and theoretical yields?
READ Ch 8.6 (pg )
Write Questions & Answer Questions #8 - 9 (notes side) Highlight answer

20. Percent Yield You can calculate this amount using stoichiometry!
Percent Yield is a ratio that tells us how ________________ a chemical reaction is.
The higher the % yield, the more efficient the reaction is. (How good is your data!!)
Actual Yield
Theoretical Yield
The ___________ yield is the amount you experimentally get when you perform the reaction in a lab. (Your result)
The _______________ yield is the amount you are ideally supposed to get if everything goes perfectly. (No errors in lab - what you should have got).
You can calculate this amount using stoichiometry!
efficient
% Yield =
x 100
actual
theoretical

21. Actual Yield and Percent Yield
The Percent yield is always less than 100%.
Why???
Errors happen.
Some of the product does not form.

22. b. Given: actual yield 86.4 g NaCl (PRODUCT) Find: percent yield
Left side - Leave about 10 spaces between each problem
Practice Problem #1
USE INFO FROM CH 8.5 TN!!
a. Example: 2Na(s) + Cl2(g)  2 NaCl(s) Given (grams): 53.2 g Na and 65.8 g Cl2 Find: limiting reactant and theoretical yield of NaCl.
b. Given: actual yield 86.4 g NaCl (PRODUCT) Find: percent yield

23. Find: limiting reactant and theoretical yield of Cu
Left side - Leave about 10 spaces between each problem
Practice Problem #1
USE INFO FROM CH 8.5 TN!!
a. Example 8.6: Cu2O(s) + C(s)  2 Cu(s) + CO(g) Given (grams): 11.5 g Cu2O and g C
Find: limiting reactant and theoretical yield of Cu
b. Given: actual yield 87.4 g Cu Find: percent yield