1. No category

.:,:.;+:+:÷:
JANUARY 22
:
, i.!
MLK Day
23
24
25
26
Investigation: All
That Remains (pg.
Notes #1
Notes #2
Cu-Fe Lab: Day #2
Mol-> mol
Other Unit
(pg. ii-12)
2)
conversions
conversions
(pg. 11-12)
Extra
Stoichiometry
Practice
Cu-Fe Lab: Day #1
HW: Complete
HW: Assessment
HW: Assessment
HW: Extra
pg. 2
pg. 5 & pg.12
pg. 8-9
Practice pg. 10
29
30
Notes #4 -
Test Review Due
31
UNIT 9 TEST
Percent Yield
(pg. 18-20)
(Pre-lab only)
27
Notes #3 -
28
QUiZ
Limiting Reagent
Cu-Fe Lab: Day #3
(pg. 11-12)
HW: Assessment
pg. 15
HW: Complete
pg.12
HW: Assessment
HW: Study for
pg. 17 & Review
Test
h
Name:
Class Period"
tDa te ..... .
¢,
.
r
Investigation: All That Remains
Predict the outcome and then test your prediction: How much solid mass will remain after decomposing 2.00g
of sodium hydrogen carbonate by heating? (Hint: 2NQHCO3(s) -ÿ> Ncl2CO3(s) + C02(g) + H20(g)) //*'
ediction (include your reasoning):
/."
Design: Hÿn your investigation with your team. Write your procedure, including any diagÿdms, in the space
below, Be pÿpared to discuss your plan with the class.
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.!z,
Safety: Discuss safety precautions that must be used and list them be!6iw.
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Investigate: After class discussion,\write in the space below a!ÿy changes to your original procedure.
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Data and Calculations:
ÿ'
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,
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Analysis and Conclusions:
,"
¢
1. How did your final masÿ'compare with your prediction? ':
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7
f
ÿ
2. What did you observe
as you heated the sodium hydrogen carbonate,?
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ia
3. Does yo inal mass measurement include wither the water or carbon dÿoxÿde products? Explain.
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%
4. /Dÿes your result match your prediction? Why or why not?
%
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y.
. Is there a limiting or excess reagent? Explain.
2
NOTES #1: MOL TO MOL CONVERSIONS
RECALL: Balancing Chemical Equations
Directions: Using coefficients, balance the following equation -
CoH6 +
H20
02 ÿ Iÿ;+ÿ C02 +
Cooking Analogy:
® 'Grill Master K.T. Tiger has the art of grilled cheese sandwich making down to a science. The Grill
Master's recipe requires 2 pieces of cheese between 2 slices of bread, grilled to perfection. What is the
coefficient ratio of the ingredients to the product?
+
Grill Master Tiger knows that a 20 pack of sliced bread and a 20 pack of sliced cheese will always make
the same number of grilled cheese sandwiches with no leftovers. How many?
® What happens to the Grill Master's grilled cheese sandwiches if he changes the quantities of
ingredients? Will he have enough ingredients? Will there be leftovers?
o Practice grilled cheese sandwich making here:
http://phet.colorado.edu/en/simulation/reactants-products-and-leftovers
What Cooking Really Is...
STOICHIOMETRY:
+
• N2 (g) + 3H2 (g) --) 2NHs (g)
•
++
'/
o How many molecules of each reactant are required to produce 2 molecules of product? Ratio?
+ ++÷+ + ....
o How many moles of each reactant are re(
)roduce 2 moles of product? Ratio?
Instead ofjcups, teaspoons, or tablespoons, we have...
1. l'++ Cÿ ÿ)'f ( -+ ÿ ÿ + !ÿ ÿ:+i+ÿ ÿi,: i'+ÿ
® ÿ_ molecule of nitrogen gas reacts with +++ÿ)molecules of hydrogen gas to produce __ molecules
of ammonia gas.
It's always in the same coefficient ratio; just like 2 slices of bread plus 2 slices of cheese produce 1
grilled cheese sandwich!
3
" ._L mol of nitrogen gas reacts with ÿ mol of hydrogen gas to produce __ mol of ammonia gas.
3. mo55
o Law of conservation of mass says mass of reactants must
o Mass of nitrogen gas =
mass of products.
and mass of hydrogen gas = (f)ÿ
, Their sum equals the mass ofÿe products= ÿ__ÿLÿ 0 ÿ
]
.
® 1 mol of gas =
a 0ÿ: q L
at Standard Temperature and Pressure (STP)
o ÿ, Lÿ L L of nitrogen gas reacts with ÿ'ÿ
L of hydrogen gas to produceÿ €ÿ
of ammonia.
Example" Interpret the number of representative particles, moles, masses, and volumes of the following:
2HzS (g) + 302 (g) -) 2SO2 (g) + 2H20 (g)
Why is this equation thrown in here in between discussion of the synthesis reaction of ammonia?
Mol to Mol Conversion Calculations:
® N2(g) + 3Hz(g) -) 2NH3(g)
o What is the mole coefficient ratio of the above equation?
• Because we know the ratio, we can calculate to find the number of moles of another substance.
Example: How many mol of NH3 are produced when 0.60 mol of nitrogen gas reacts with hydrogen gas?
Practice Problems
Directions: Using the balanced chemÿ equation, calculate the followinÿl con versions-
IVÿOz + 4HCI -ÿ MnCI4+ 2Nÿzÿl
1. How many moI of H20 are produFedÿwhen 3.20 rnÿ of MnO2 reacts with hydrochloric acid?
2. How many tool.of HCI are consumed (used) when 1.65 mol of Manganese (IV) chloride are produced?
3. How many mol of water are produced when 4.35 moles of MnCI4 are also produced?
'\
4
Assessment: interpreting Coefficients as Moles
CH, (g) + jÿO2 (g) -)' CO2 (g) + ÿ H20 (g)
1. How many tool of carbon dioxk
li
/?_
are formed when 40 tool of OXÿgLÿOj is consumed?
I s 4k
......... ÿ< ÿy7ÿ-ÿ
I
fÿ
2, How many mol of methane ÿCÿ))are needed to tÿorm 200 tool ÿ)@ter?
3. How many mol of oxÿ(Oj combine with 0,05 mÿlÿfÿmethane (CHÿ)?
NO (ÿ) + ÿqÿ (g) --> ÿNOÿ (g)
4. How manymol
(02) combine with 500, mol of NO?
i
5. How many tool of NOz are formed from 0.25 mol of NO?
jÿ)---ÿ----ÿ--ÿÿ.ÿ Jÿ 0d
,
a,
If you have 80. tool of NO, how many mol of oxygen (02) would you use?
r 4tVO)
b. If you had started with 200. tool of oxygen (0ÿ), how many would you have left?
ÿ.
ii
NOTES #2: MASS TO MASS AND OTHER UNIT CONVERSIONS
RECALL: The Mole Highway.,.it's been expanded and construction is completel
Like before, the Mole Highway can be used as a map toward setting up an appropriate conversion
HOW IT'S USED:
1. Find the starting point; use the value, substance, and unit you are given
2. Find the ending point; use the value, substance, and unit are you being required to solve
3. You must stay on the highway]ll
4. Each road taken represents 1 step in your conversiont
5. Once the destination is reached, solve mathematically by multiplying across the top, multiplying
across the bottom, and dividing the top value by the bottom value.
,iI'
GIVEN
WANTED
molar mass
= 2 mote
molar rnaÿ;s
[Volume
22.41
1mole
eqn)
6,0ÿ
1mole
6.02ÿ
]es = 2mole
Representative Particles1 Representative Particles I
(atoms, |ons, molL=cules, formula units} I
(atoms, mnsÿ molecule.s1 formula u. s)j
!
NOTE:
1. Before any math can be done, a BALANCED CHEMICAL EQUATION is required.
2. If the starting value isn't in the unit "mol," yourfirst step is to convert it there.
3. Going from real of substance A to real of substance B requires a Mol to Mol conversion; USE YOUR
COEFFICIENTS FROM THE BALANCED CHEMICAL EQUATION I
Mass to Mass Conversion Calculations
• Nz(g) + 3Hz(g) -> 2NH3(g)
• Like yesterday, in order to go from the mass of one substance, to the mass of a new substance, a tool to
tool conversion will be necessary,
Example; Calculate the number of grams of NH3 produced by the reaction of 5.40 g of H2 with excess N2 (g).
6
Practice Problems - ALL UN ITS
............................. ÿÿ4"WriteailÿJÿnceclformula, and then set up your conversi0n caicuÿons,***
l. How many giÿa'ÿs of 02 (g) are produced when a sample of 29,2 g of ÿer decomposes?
I1,o:ÿ3 Ao
iÿ ÿnÿHÿo j ÿS.o,
2, Using the same equation, how many liters of hydrogen gas are produced when 1,33 x :101ÿ molecules of
,t
4, How many molecules of oxygen are consumed in the formation of :1.87.4 L of SO37
5ÿ How many molecules of Sulfur dioxide are consumed tn the formation of 4.43. x 3.0ÿz molecules of sulfur
trioxide?
r X i?
7
Assessment: Mixed Mole Conversions
,
Find the molar mass of the following:
a. lmolofCH4=
b. I tool of Ag2SO4 = ÿÿg of Ag2SO4
c. 1 mol of PzOs= ÿ 3,ÿ6ÿ.g of P2Os
d.
g of NaBr = I mol of NaBr
e. ÿ ÿ,ÿkg of AI(NOÿ), = 1 mol of AI(NO3)3
f ÿ1,%5ÿ g of Ba,(PO,), = 1 tool of Ba,(PO,)2
\
)
How many lite
H4 are needed to produce 0.38 grams ÿf-ÿ2;ÿ-'% at STP?
¢
4. How many molecules of C02 are produced from 12.9 grams of 02?
,i
)
Bas(P04)= + ..ÿHI (g)-> ÿBal, + .=ÿH=P04
5. How many grams of Balÿ are produced from 4.37 x :1.0aÿ molecules of HI?
Y
6. How many formula units of Bal2 are produced from 96.2g of HI?
7. How many grams of H3P04 are produced from 2.0 moles of Ba3(P04)2?
8. How many liters of HI are needed to produce 72.54g of Bal2 at STP?
9. Practice drawing the expanded Mole Highway from memory. Remember, the only addition is that Mol
can now be converted to Mol.
Mass, Volume, and Particle Stoichiometw Extra Practice
1. If you have 1.9ÿ02s molecules of ethane (C2H6), how many molecules of oxyÿOare
!
needed to react
completely?(molecules=partides,)ÿ£;ÿ41,o ÿ70ÿ, ÿ // COco } ÿ1-t$0
L_
ÿ¢are needed to
2. Aluminum aÿ,cksulfur react to produce aluminum sulfide. How many grams of s
pr°duce186ÿams°faluminumsulfide?ÿAI "ÿ3ÿ' ÿ AiagJ
H
0'I
,
s,
,r
3. Ammonia and water combine to proidÿe ammonmm'6ydroxide. At S]P, how many liters ÿr are
needed to produce 6.54 liters of aÿum hydroxide?
4. How many atoms of phoÿ,.ÿ_s are needed to produce 16.0 x 10 m
les of phosphine (PH3)?
(atoms & molecules = particles!)
20 +3": ->2..:
, - Oaÿ
4}
,
How many grams of o
%
are needed to produce 6.55 x 1024 formula units of potasSiUm oxide?
g ÿ + o: -->ÿ:o?
.
p
Ydÿoÿ gas will be proAed if 38.5g of hydrochloric @cÿ.ÿreacts with zinc?
Zn + <ÿ{-ICl --> ZnC:I2 + Hÿ
;
NOTES #3: Limiting Reagents (Reactants)
Demo: Exploring Limiting Reagents
HC2Hÿ02 + NaHC03 --) NaC2H302 + C02 + H20
Experiment
Mass of NaHC03
Moles of HC2H302
1
0.10g
2
1.50g
0.01 moles
3
4.0g
0.01 moles
Size of Balloon
0.01 moles
1. In Experiment #1, what do you think was limiting the size of the balloon?
2. Verify your answer in the previous question through calculations.
3. Explain the difference or lack of difference between the ÿaliooÿiÿn Experiment #2 and #3.
Now back to cooking
.....
!ÿiÿ ÿÿ
1. What is Grill Master Tigers, recipe for grillÿdÿchÿse sandwiches?
2. What happens if the Grill' Master regeivÿnÿyhalfÿ: ÿ of his order of cheese for the day?
.......
ÿJÿ"
,ÿ
ÿ
.
3. So, In this case, what is hmÿnÿhÿ nuÿbeÿ[ of gnlled cheese sandwiches he can make?
4. What if the Grill Master received3 times the amount of cheese he needed?
5. What would be limiting him in this case?
Limiting Reagent (aka Limiting Reactant)
The same thing applies to chemical reactions...
o N2 (g) + 3H2 (g) ÿ 2NH3 (g)
o
__ mol of N2(g) reacts with __ mol of H2 (g) mol to form __ mol of NH3 (g).
o What happens if you only have 0.5 mol of nitrogen gas?
• How much hydrogen gas would you use?
• How much ammonia would you make?
Limiting Reagent/Reactant:
Excess Realÿent/Reactant:
13
o2UR
® Example: Sodium chloride can be prepared by the reaction of sodium metal with chlorine gas.
Suppose that 6.70 mol of Na reacts with 3.20 tool of C12. What is the limiting reagent?
Follow these five steps
....
'
ÿÿt
> .. Step 1:
> Step 2:
o To do this, convert the given info for each reactant (mol, in this problem) to mol of product.
® If the original substances are given in grams, you'd have an extra step - converting mass to moles but the rest of the process would be the same.
, NOTE: If the original substances are given in grams, what do you need to do before this step?
o Convert to mol.
> Step 3'
® You will have __ answers for moles of product. Why?
o So which one do I use?
o The
of the two answers is the
because
you only have enough reactants to make that amount. You will run out of the reactants before the
larger amount is made.
o From this, you can figure out your limiting reagent and excess reagent.
>
Step 4;
o Once you know your maximum product, look all the way to the
reactant that produced that smaller amount of product is your
of that calculation. The
o It "limited" you to making the
. The other reactant - that started the other calculation - is the
> Step S:
- Convert mol of your limiting reagent to mol of product (or whatever the original question asks for).
Practice Problem 2ÿ'cOuOÿsÿÿ) ÿ,ÿ, 0 ÿ"ÿÿI
+ s (s) -> cu2S (s)
1. What is the ,ilÿitirÿ.ÿgrÿagentÿwÿen 80.0 g Cu reacts with 25.0 g of S?
.
,
2. What is the maximum number ÿf Copper (I) sulfide produced?
......
.-!
.........
14
,
Assessment: Limiting Reagent/Reactant
Directions: Reference Notes #3 to complete the `following Limiting Reagent word problems. Find a balanced
chemical equation if necessary and follow the`four steps. ,.% ÿ ÿ
+
mol of H2 and 4.0 tool of 02?
Cu + AgNOÿ --> ÿ.Cu(NO3)2 + Ag
5. How maÿy to!! of
-
an be produced from 6.3 tool of Cu and 4.2 moles of AgNOÿ?
%
\
6. Whatÿmass of Cu(NO.ÿ)z can be produced from 5.5 g Cu and 1.95 g AgNOÿ?
7. How many ÿol ofAg cÿn be produced from 1.5 g Cu and 7.2 g of AINOÿ?
15
NOTES #4: Percent Yield
Cooking, yet again... ©
o Grill Master Tiger's recipe yields 10 grilled cheese sandwiches when 20 slices of bread and 20 slices of
cheese are used
® So, the recipe tells you the theoretical yield:
--ÿ
o 'What you actually make is the actual yield:
e Percent yield:
> Formula:
Food jfor Thought: Could the perc
yield to vary?
X
i dnormally be larÿLgyÿthan 100%? Smalier? What might cause the %
I
f ÿ_ "
Example: Using the following equation, what is the theoretical yield of CaO if 24.8g CaC03 is heated? What is
the percent yield if 13.1g of CaO is produced?
® Followthe steps below...
o Step 1: Convert grams of the given substance to grams of the questioned substance.
, Which means...
- 24.8 g ofCaC03 =ÿg of CaO.
o Step 2: Use the formula to find percent yield.
/
ÿ: iÿ
Assessment: Percent Yield Applications
Directions: Reference Notes #4 to complete the following percent yield word problems. All work must be shown.
A baker has a recipe for cookies that says he can bake a yield of 250 cookies. However, when he does
.
bake them, he finds that he can only make 125. What is the percent yield?
{Assume that all cookies are the exact same size as directed by the recipe)
J
H. "ÿ chemist runs an experiment and produces 100 g of sulfuric acid. The All-Knowing Chemistry Book
states he should have made 123 g of sulfuric acid. What is the percent yield?
1
\
3.
...........
A gazelle in Africa wants to make Leaf-let Supremes for the animals of the Pride Land. He follows a
recipe that has been passed down through the generations and expects to make 2,300 servings, as there
are many animals in the Pride Land. However, after much time and effort, he co-rnes-t
that the
recipe will only make 1,980 servings. What is the percent yield?
4ÿ-
A monkey who has beentrained in pharmacology performs an experiment in which he produces 14.69 g
of fern tree seeds. He doesn't feel this is correct, and looks in the All-Knowing Pharmacology Book to
find he should have made 15.75 g. What is his percent yield?
t '. ,
L
,
.
ii
J
A farmer out checking his fields looks in on his Hawaiian flower tree. He notices only 15 blooming
flowers. This is 73% of what it should be. What is the Hawaiian flower tree's theoretical yield?
A man shelling pecans notices that each pecan is only producing 39% of the meat expected. In the
Pecan Man's Handbook, he reads that each pecan should have a mass of 200 g. What is the actual yield
of each, pecan?,ÿ?% :
] ,ÿ ,!,ÿ ,\ÿ?
I \-, "ÿ
:]
.
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• -,
,
iÿ1
[ )( ÿ
ÿ
=i > -
i
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',,
;ÿ
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,
A chemist is working in his lab and does an experiment that produces 0.72 g of the cure for boredom.
From his calculations, this is only 84% of what it should produce. What is the theoretical yield for this
cure?
8. A dairy farmer has changed his feed and is impressed with how much milk his cows are producing. The
new feed claims to increase a cow's milk production by 150 g per day; however, his cows a:re currently
producing at a yield of 92%. What is the actual amount of increase in milk production?
,.
,7
°
i
Academic Chemistry Unit 9 Test Review (Due on Jan 30th!
STOICHIOMETRY TEST on Fridayn January 31st
.
Define the following:
a. Stoichiometry
b. Limiting reagents
c. Excess reagents
d. Percent Yield
e. Actual Yield
f. Theoretical Yield
2. Find the molar mass of the following:
a. _ÿ. ÿ gofCs2
c. ÿ'ÿ,ÿ(ÿgofP2Os
b. 11ÿ1ÿ'ÿ'ÿ gofAg,P04
Directions: Balance the following equations and perform the appropriate conversions and calculations.
HCI "ÿ ÿH2 +
C!2
3. How many grams of HCl are needed to produce 5.2 moles of Cl2?
, ÿ ÿ mob I-ÿ(-
.
379 or
How many moles of H2 are produced from 6.3 L of HCI at STP?
,ÿL. HOI I rnÿHcl ÿ t rÿ01 ÿ!______ÿ
18
5. How many moles of CI2 are produced from 12.9 grams of IilCI? (see equation on previous page)
BaS04 + _ÿ. Hl(g) ÷
,/
Bal2 + ÿH2S04
6. How many moles of Bal2 are produced from 7.6 moles of HI?
I
I
7. How many grams of Bal2 are produced from 9.2Lof HI at STP?
,
How many grams of H2S04 are produced from 2.0 moles of BaS04?
'
=
¢
i
.
I
i
How many molecules of HI are needed to produce 72_ÿg of Bal2?
10. What is the volume of H2S04 produced from .035 grams of HI at STP?
L
IN,q 1ÿ H;
2, moÿH::C
19
11. Balance the followifig eqgation ancÿ-nsweJthe questions that follow:
a. What is, theolimitingreagent if 36.0g of water reÿacts with 1 '
c
: "
of Fes04 were produced, what is the percent yield of the reaction?
20
' " " ÿ"
Name:
Date:
Class:
PERCENT YIELD
1)
The actual amount of product formed in a reaction is 39.7 grams although your calculations predicted 65.6
grams would form. What is the percent yield of this product?
2) ÿAICI3 -> ÿA + ÿCI2
What is the theoretical #ield of aluminum in grams, if 56.8 grams of aluminum chloride decomposes?
.....
.
......
.....
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....
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I
3) If only 10.6 grams of aluminum is produced from the reaction in Question #2, what is theperceng.Tield?
4)
Fe203 +ÿCO -> ÿFe +ÿC02
hat is the percent yield of iron if 84.8 grams of iron (III) oxide reacts with an excess of carbon monoxide
and forms only 54.3_,£rams of iron?
.... =
\
1-
! :i} /i
£ i+ ,.ÿ,,
< =< .-ÿ
5)
<,
Nitrogen and hydrogen react to form ammonia. (Write andbalance this reaction before continuinq!) What is
the percent yield of NH3 in the above reaction if 5.50 grams of hydrogen reacts with excess nitrogen to form
I I