a. Write the formula of calcium nitrate.
b. Calculate the percent composition of calcium nitrate. (24.4% Ca,
17.1% N, 58.5% O)
c. A compound is 69.6% manganese, the rest is oxygen. Calculate the
empirical formula. (Mn2O3)
d. If one form of the previous compound has a molar mass of about 475
amu, calculate the molecular formula.
Moles
Moles
What coefficients mean:
2 Na +
Cl2 
2 Na
1 Cl2
4 Na
4Cl2
Reaction Stoich.
2NaCl
2NaCl
Moles
Reaction Stoichiometry
2 Na +
Cl2 
6 moles Na
10 atoms Na
2NaCl
ONLY WORKS FOR
MOLES, MOLECULES, ATOMS
1. How many moles of H2 and O2 must
react to form 6 moles of H2O?
2. How many moles of water must react
with 0.25 moles of CaC2?
CaC2 + 2H2O  C2H2 + Ca(OH)2
3. How many moles of KCl and O2 are
formed from the decomposition of 6
moles of KClO3?
4. How many grams of oxygen are
needed to react with 4.41 g of Li to
form Li2O? (Ans: 5.08 g)
5. How many grams of oxygen are needed to
react with 17.5 g of Al? (Ans: 15.6)
Al + O2  Al2O3
6. How many grams of oxygen will react
with 25.0 g of C2H6? (Ans: 93.3 g)
C2H6 + O2  CO2 + H2O
7. How many grams of P4 and O2 are
needed to make 3.62 g of P2O5?
(Ans: 1.58 g, 2.04 g)
P4 + O2  P2O5
Calculate the mass of aluminum required
to produce 750.0 g of iron. Also
calculate the formula units of Fe2O3
that are used in the process.
Al +
Fe2O3  Al2O3 + Fe
363 g Al, 4.05 X 1024
What mass of oxygen is needed to react with
16.7 g of iron to form Iron(III)oxide?
How many molecules of O2 are used?
4Fe + 3O2  2Fe2O3
Ans: 7.18 g, 1.35 X 1023 atoms
KClO3 decomposes into potassium chloride
and oxygen. If you start with 50.0 grams of
KClO3, calculate the mass of each product
that forms.
Lead(II)Nitrate reacts with potassium iodide
to form potassium nitrate and
lead(II)iodide.
a. Write the balanced reaction
b. What type of reaction is this?
c. Calculate the grams of potassium nitrate
formed from the reaction of 18.0 g of
lead(II)nitrate. (11.0 g)
d. Calculate atoms of iodine in the lead(II)
iodide. (6.54 X 1022 atoms I)
The following problems refer to FeSO4
a. Is the compound ionic or molecular?
b. Write the proper name of the compound.
c. Calculate the oxidation state of the sulfur in the
SO42- ion.
d. Write the reaction that would occur between
FeSO4 and NaCl.
e. Calculate how many grams of NaCl are needed
to react with 15.4 grams of FeSO4.
Moles
Limiting Reactant
1. Sandwich analogy:
14 slices of bread
4 pieces of turkey (low fat)
Maximum # of sandwiches?
2. Limiting Reactant – Totally consumed in a
reaction. No leftovers
(CuSO4 and Al wire demo, heat soln first)
1. How many grams of H2SO4 can be formed from
the rxn of 5.00 moles of SO3 and 2.00 moles of
H2O?
SO3 + H2O  H2SO4
(Ans: 196 g)
2. How many grams of H2O can be formed
from the rxn of 6.00 moles of H2 and 4.00
moles of O2?
O2 + H2  H2O
3. How many grams of NaCl can be formed
from the reaction of 0.300 mol of Na and
0.100 mol of Cl2? (Ans: 11.7 g)
2Na + Cl2  2NaCl
4. How many grams of Ag can be formed from the
rxn of 2.00 g of Zn and 2.50 g of silver nitrate?
How much excess reactant remains?
Zn + AgNO3  Ag + Zn(NO3)2
(Ans: 1.59 g Ag, 1.52 g xs zinc)
5. How many grams of Ag2S can be formed from
the rxn of 15.6 g of Ag and 2.97 g of H2S?
(Assume O2 is in excess)
4Ag + 2H2S + O2  2Ag2S + 2H2O
(Ans: 18.0 g)
6. How many grams of CO2 can be formed from
the rxn of 40.0 g of CH3OH and 46.0 g of O2?
2CH3OH +
(Ans: 42.2 g)
3O2  2CO2 + 4H2O
7. How many grams of Ba3(PO4)2 can be formed
from the rxn of 3.50 g of Na3PO4 and 6.40 g
of Ba(NO3)2? (Ans: 4.92 g)
Na3PO4 + Ba(NO3)2  Ba3(PO4)2 + NaNO3
1.
Calculate the mass of aluminum required to
produce 750.0 g of iron. Also calculate the
formula units of Fe2O3 that are used in the
process. (363 g Al, 4.05 X 1024 form. units)
Al + Fe2O3  Al2O3 + Fe
2. If 35.60 grams of NaOH is reacted with 30.80 grams
of H3PO4,
3 NaOH(aq) + H3PO4(aq) → Na3PO4(aq) + 3 H2O(l)
a.
b.
How many grams of Na3PO4 are formed? (48.7 g)
How many grams of the excess reactant remains
when the reaction is complete? (1.67 g)
Moles
Percent Yield
A. Formula:
Actual Yield
X 100 = % Yield
Theoretical Yield
1. What is the % yield if you start with 10.00
grams of C and obtain 1.49 g of H2 gas?
C + H2O  CO + H2
(Ans: 89.2%)
2. Carbon was heated strongly in sulfur(S8)
to form carbon disulfide. What is the
percent yield if you start with 13.51 g of
sulfur and collect 12.5 g of CS2?
4C + S8  4CS2
(Ans: 78.0%)
Calculate the percent yield of the following
reaction if 60.0 grams of CaCO3 is heated to
give 15.0 grams of CaO?
CaCO3 → CaO + CO2
[44%]
3.
An aluminum ladder oxidizes according the following unbalanced
equation:
Al + O2  Al2O3
a.
b.
c.
d.
100.0 grams of aluminum reacted with excess oxygen. Calculate the
theoretical yield. (189 g)
If the percent yield was 67.4%, calculate the actual yield. (127 g)
Calculate how many grams of oxygen were used. (88.9 g)
Identify the type of reaction that occurred.
11.5 grams of sodium reacts with 15.0 grams of chlorine (Cl2) to form
sodium chloride. 18.2 grams of NaCl are collected.
a.
b.
c.
d.
e.
Write the balanced chemical equation.
Identify the limiting reactant.
Calculate the theoretical yield of NaCl. (24.7g)
Calculate the percent yield. (73.7%)
If the percent yield for a different trial (starting with same amounts)
was only 60.4%, calculate the actual yield. (14.9 g)
f. Identify the type of reaction that occurred.
The percent yield of the following equation is
55%.
SO3(g) + H2O(l)→H2SO4(aq)
a. Calculate the theoretical yield of H2SO4 when
160.0 grams of SO3 are combined with excess
water? (196 g)
b. Calculate the actual yield (108 g)
Moles
1. Molarity = measure of the
concentration of a solution
2. Molarity = moles/liter
Similar to Density = g/L
Molarity
Moles
3. Which is more concentrated?
1 M HCl
3 M HCl
Molarity
Moles
Molarity
1. What is the molarity of a soln that
contains 49.05 g of H2SO4 in enough
water to make 250.0 mL of soln? (Ans:
2.00 M)
2. What is the molarity of a soln made by
dissolving 23.4 g of Na2SO4 in enough
water to make 125 mL of soln? (Ans:
1.32 M)
3. What mass of HCl is present in 155
mL of 0.540 M HCl? (Ans: 3.06 g)
4. How many grams of NaOH are in
5.00 mL of 0.0900 M NaOH? (Ans:
0.018 g)
5. What volume of 0.0900 M NaOH is
needed to provide 0.00058 moles?
(Ans: 6.44 mL)
6. What volume of 0.0764 M HCl is
needed to provide 0.0694 g of
HCl?(Ans: 25 mL)
Moles
Mixing From a Solid
1. Mixing from a solid
2.
How would you prepare 350.0 mL of 0.500 M
Na2SO4?
1. Mass 24.9 g of Na2SO4.
2. Dissolve in a small volume of water.
3. Dilute to 350.0 mL.
3. Write directions for the preparation of
500.0 mL of 0.133 M KMnO4 (10.5g)
4. Write directions for the preparation
of 250.0 mL of 0.00200 M NaOH
(0.02 g)
1. Mass 10.5 g of KMnO4.
2. Dissolve in a small volume of water.
3. Dilute to 500.0 mL.
1. Mass 0.02 g of NaOH
2. Dissolve in a small volume of water.
3. Dilute to 250.0 mL.
Diluting from a Solution
1. Dilution Formula:
M1V1 = M2V2
2. Used when you are starting with a more
concentrated soln. (Grape juice concentrate,
Coke syrup)
3. What is the molarity of a soln of KCl that
is prepared by diluting 855 mL of 0.475 M
soln to a volume of 1.25 L? (Ans: 0.325
M)
4. You have a 3.00 L bottle of 11.3 M HCl.
What volume of it must be diluted to make
1.00 L of 0.555 M HCl? (Ans: 49.1 mL)
How would you prepare 500.0 mL of 0.100 M
NaOH from a 2.72 L bottle of 0.463 M NaOH?
The
following questions refer to a 0.0987 M solution
Moles
of NaNO3.
a. Calculate how many grams of NaNO3 are present
in 50.0 mL of the solution. (0.419 g)
b. Calculate the volume of the solution required to
provide 0.188 grams of NaNO3. (22.4 mL)
c. State how you would prepare 500.0 mL of the
solution starting with solid NaNO3. (4.19 g)
d. State how you would prepare 500.0 mL of the
solution starting with a large 3-L bottle of 2.00 M
NaNO3(aq) (24.7 mL)
c. 1) Mass 4.19 g of NaNO3
2) Place in a small volume of water to dissolve
3) Dilute to 500 mL
d. 1) Measure 24.7 mL of 2.00 M NaNO3
2) Dilute to 500 mL
11.5 grams of sodium reacts with 15.0 grams of chlorine (Cl2) to form
sodium chloride. 18.2 grams of NaCl are collected.
a.
b.
c.
d.
e.
Write the balanced chemical equation.
Identify the limiting reactant.
Calculate the theoretical yield of NaCl. (24.7g)
Calculate the percent yield. (73.7%)
If the percent yield for a different trial (starting with same amounts)
was only 60.4%, calculate the actual yield. (14.9 g)
f. Identify the type of reaction that occurred.
The following questions refer to the following
unbalanced reaction of ethanol (C2H5OH )
C2H5OH + O2  CO2 + H2O
a. State what type of reaction is occurring.
b. Calculate the grams of oxygen needed to react
with 100.0 grams of ethanol.
c. Calculate the number of CO2 molecules
produced.
d. The density of ethanol 0.789 g/cm3. Calculate
the volume of ethanol needed to provide 100.0
grams.
The
following
questions
refer
to
this
equation:
Moles
H2SO4 + NaOH  H2O + Na2SO4
a. Calculate how many moles of NaOH are present
in 25.0 mL of 0.100 M NaOH.
b. Calculate how many grams of Na2SO4 are
produced if the 25.0 mL of 0.100 M NaOH reacts.
c. Calculate the moles of H2SO4 that would be
required.
d. Calculate the volume of H2SO4 required if the
concentration is 0.0800 M.
e. State what type of reaction occurred.
Moles
5. a) 10.0 mol b) 1.67 mol
5. a) 10.0 mol
Moles
b) 1.67 mol
7. a) 21.9 g
b) 29.3 g c) 6.60 g
11 a) 83.6 g
b) 5.74 mol
c) 279 g
d) 0.430 g e) 175 g
13. 363 g Fe, 4.05 X 1024 Fe2O3
15. 16.5 g Cu
18. 323 g Cl2
23.a) 1.60 mol
b) 1.50 mol
c) 2.81 mol
d) 1.90 mol
27.39.4 g
30. 8.80 g CO2, 10.4 g HCl
23.a) 1.60 mol
b) 1.50 mol
mol
d) 1.90 mol
25. 0.133 mol Al remaining
26. 695 g CO2
27. 39.4 g
c) 2.81
28. 0.750 mol
29. 16.9 g AgCl, 3.5 g CaCl2
30. 8.80 g CO2, 10.4 g HCl
32. 30.0 g, 70.7%
33. 47.0 %
34. 13.8 g
35. 86.4 %
37. 103 g H2
38. 16.4 g
33. 47.0%
Moles
34. 13.8 g
38. 16.4 g
12-23. 0.542 M
12-24 a) 0.872 M
b) 1.40 M
c) 12.4 L
d) 41.4 g
e) 0.294 M
f) 0.024 mol
g) 307 mL
h) 49.0 g
i) 2.00 mL
12-26. 22.5 g
Moles
12-27.
12-35.
12-37.
12-40.
2.67 L
1.27 M
0.710 L
2541 mL
Sodium bicarbonate (NaHCO3) was decomposed
Moles
to compare the actual mass of sodium
carbonate (Na2CO3) to the theoretical mass.
About two grams of NaHCO3 was placed in a
petri dish. The dish was heated on a hotplate,
allowed to cool, and then massed. The
theoretical mass of Na2CO3 was calculated
from the chemical equation and compared to
the actual mass. This experiment was accurate,
with a percent error of 5.3%. The experiment
was not precise because it produced a range of
0.80 grams in the actual mass of Na2CO3.
1 2 3 4 5 6 7 8 9 10
C D C D B B C C A D
11 12 13 14 15
B D B D D
4.
Na2S(s)  2Na+(aq) + S2-(aq)
Lab Notes
• Goggles
• Use aluminum pans instead of petri dishes
• 4 trials total – Mark your dishes
• Wash dishes out at end and leave all materials at
station
• BE CLEANER ABOUT THE BALANCE!!!!!
• Ignore back of sheet, use AP lab report format
• All work must be unique
Reaction Stoichiometry
1. 111 g
2. 9.73 g
3. 104 g
4. 131 g
5. 19.4 g
6. 356 g
7. 16.1 g
8. 40.9 g
9. 22.5 g
10. 1.13 g
11. 31.9 g
12. 71.4 g
Stoichiometry: You write the reaction
1. 48.4 g
2. 47.2 g
3. 3.78 g
4. 68.3 g
5. 18.3 g
6. 267 g
7. 181 g
8. 0.387 moles
9. 14.5 g
10. 63.8 g
Molarity (WS)
1. 0.926 M
2. 53.3 g
3. 2.45 mL
4. 1.13 M
5. 21.2 g
6. 173 mL
7. 0.280 M
8. 34.5 mL
9. 0.142 M
10.8.20 mL
11.
12.
13.
14.
29.9 mL
0.0927 M
39 mL
Same
Writing Directions (WS)
1. Mass 9.88 g, dissolve in small volume, dilute to 1 L
2. Mass 1.85 g, dissolve in small volume, dilute to 750 mL
3. Mass 0.189 g, dissolve in small volume, dilute to 17 mL
4. Mass 4.69 g, dissolve in small volume, dilute to 600 mL
5. Mass 4.80 g, dissolve in small volume, dilute to 500 mL
6. Mass 5.20 g, dissolve in small volume, dilute to 1 L
7. Mass 32.0 g, dissolve in small volume, dilute to 850 mL
8. Mass 14.4 g, dissolve in small volume, dilute to 500 mL
9. Mass 6.11 g, dissolve in small volume, dilute to 250 mL
10. Mass 2.20 g, dissolve in small volume, dilute to 100 mL
100 g
2.69 mol
1.79 mol
100 g
1.79 mol
2.69 mol
4.83 g
169
21.3 g
Moles
Moles
Moles
Moles
Moles
Moles