1. Ch Stoichiometry
N2(g) H2(g) NH3(g)

2. 1N2(g) H2(g) NH3(g)
1 mole reacts with 3 moles to produce 2 moles
Masses:
= 28.0 g/mol
= g/mol
= 14.0
= 3.0
17.0 g/mol
How many moles of NH3 produced?
- 2 mol of N2 react?
- 1½ mol of H2 react?
- 28 g of N2 react?

3. Ex1) Calculate the # of moles of nitrogen required
to make 7.24 moles of ammonia.
N H NH3
HW#1) Given 4 Al O Al2O3
How many moles of Al are needed to form 3.7 mol of Al2O3?
b) How many moles of O2 are required to react
completely with 14.8 moles of Al?

4. Ex1) Calculate the # of moles of nitrogen required
to make 7.24 moles of ammonia.
N H NH3
? moles moles
7.24 moles NH moles N2
2moles NH3 = 3.62 moles N2
HW#1) Given 4 Al O Al2O3
? Mol mol
How many moles of Al are needed to form 3.7 mol of Al2O3?
3.7 mol Al2O mol Al
2 mol Al2O3 = 7.4 mol Al
b) How many moles of O2 are required to react
completely with 14.8 moles of Al?
14.8 mol Al 3 mol O2
4 mol Al = 11.1 mol O2

5. Mass – Mass Calcs
Ex2) Calculate the # of grams of NH3 produced by the reaction
of 5.40g of hydrogen with an excess of nitrogen.
N2(g) H2(g) NH3(g)
Ex3) How many grams of nitrogen are needed to produce
the 30.6g of NH3 needed for the reaction?
N2(g) H2(g) NH3(g)

6. Mass – Mass Calcs
Ex2) Calculate the # of grams of NH3 produced by the reaction
of 5.40g of hydrogen with an excess of nitrogen.
N2(g) H2(g) NH3(g)
5.40 H2 1 mol H2 2 mol NH g NH3
2.0 g H mol H mol NH3 = 30.6g NH3
Ex3) How many grams of nitrogen are needed to produce
the 30.6g of NH3 needed for the reaction?
N2(g) H2(g) NH3(g)
30.6g NH3 1 mol NH mol N g N2
17.0 g NH3 2 mol NH3 1 mol N = 25.2g N2

7. HW#2) CaC2(s) + H2O C2H2(g) + Ca(OH)2(aq)
a. How many moles of CaC2 are needed to react completely
with 49.0g of H2O?
b. How many grams of Ca(OH)2 are produced by 5.00g of CaC2?
c. How many grams of Ca(OH)2 are produced
when 0.89 mol of C2H2 are produced?

8. HW#2) 1CaC2(s) + 2H2O 1C2H2(g) + 1Ca(OH)2(aq)
a. How many moles of CaC2 are needed to react completely
with 49.0g of H2O?
49.0g H2O 1 mol H2O mol CaC2
18.0g H2O mol H2O = 1.36 moles CaC2
b. How many grams of Ca(OH)2 are produced by 5.00g of CaC2?
c. How many grams of Ca(OH)2 are produced
when 0.89 mol of C2H2 are produced?

9. HW#2) 1CaC2(s) + 2H2O 1C2H2(g) + 1Ca(OH)2(aq)
a. How many moles of CaC2 are needed to react completely
with 49.0g of H2O?
49.0g H2O 1 mol H2O mol CaC2
18.0g H2O mol H2O = 1.36 moles CaC2
b. How many grams of Ca(OH)2 are produced by 5.00g of CaC2?
5.00g CaC2 1 mol CaC mol C2H g C2H2
52.1g CaC mol CaC2 1 mol C2H2 = 2.49g C2H2
c. How many grams of Ca(OH)2 are produced
when 0.89 mol of C2H2 are produced?
CH 12 HW#1 1-3

10. HW#2) 1CaC2(s) + 2H2O 1C2H2(g) + 1Ca(OH)2(aq)
a. How many moles of CaC2 are needed to react completely
with 49.0g of H2O?
49.0g H2O 1 mol H2O mol CaC2
18.0g H2O mol H2O = 1.36 moles CaC2
b. How many grams of Ca(OH)2 are produced by 5.00g of CaC2?
5.00g CaC2 1 mol CaC mol C2H g C2H2
52.1g CaC mol CaC2 1 mol C2H2 = 2.49g C2H2
c. How many grams of Ca(OH)2 are produced
when 0.89 mol of C2H2 are produced?
.89 mol C2H2 1 mol Ca(OH) g Ca(OH)2
1 mol C2H mol Ca(OH)2 = 66.0g Ca(OH)2
CH 12 HW#1 1-3

11. Ch12 HW#1 1-3
3) 2 C2H2(g) O2(g) CO2(g) H2O
a) How many grams of CO2 & H2O are produced when 52.0g C2H2 burn?
CO2 :
H2O:
b) How many grams O2 to burn 52.0g C2H2?
c) 2 C2H2(g) O2(g) CO2(g) H2O

12. Ch12 HW#1 1-3
3) 2 C2H2(g) O2(g) CO2(g) H2O
a) How many grams of CO2 & H2O are produced when 52.0g C2H2 burn?
CO2 : 52.0g C2H2 1 mol C2H2 4 mol CO g CO g C2H2 2 mol C2H mol CO =
H2O:
b) How many grams O2 to burn 52.0g C2H2?
c) 2 C2H2(g) O2(g) CO2(g) H2O

13. Ch12 HW#1 1-3
3) 2 C2H2(g) O2(g) CO2(g) H2O
a) How many grams of CO2 & H2O are produced when 52.0g C2H2 burn?
CO2 : 52.0g C2H2 1 mol C2H2 4 mol CO g CO g C2H2 2 mol C2H mol CO =
H2O: 52.0g C2H2 1 mol C2H2 2 mol H2O g H2O g C2H2 2 mol C2H mol H2O =
b) How many grams O2 to burn 52.0g C2H2?
c) 2 C2H2(g) O2(g) CO2(g) H2O

14. Ch12 HW#1 1-3
3) 2 C2H2(g) O2(g) CO2(g) H2O
a) How many grams of CO2 & H2O are produced when 52.0g C2H2 burn?
CO2 : 52.0g C2H2 1 mol C2H2 4 mol CO g CO g C2H2 2 mol C2H mol CO =
H2O: 52.0g C2H2 1 mol C2H2 2 mol H2O g H2O g C2H2 2 mol C2H mol H2O =
b) How many grams O2 to burn 52.0g C2H2?
52.0g C2H2 1 mol C2H2 5 mol O g O g C2H2 2 mol C2H2 1 mol O =
c) 2 C2H2(g) O2(g) CO2(g) H2O

15. Ch12.2 Mass – Mass Ch12 HW#2 4-13 Discuss Lab 12.1 (Next slide)
4) Aluminum reacts with HCl to produce aluminum chloride (AlCl3) and hydrogen gas. Write a balanced equation for the reaction and calculate the number of moles of HCl required to react with 0.87mol of Al.
5) Glucose (C6H12O6) combines with O2 in the body to produce carbon dioxide and water. Write a balanced equation for this reaction. How many moles of O2 are required to combine with 0.25mol of glucose?

16. Lab 12.1 Quantitative Analysis
Data Analysis
1) Mass of Fe lost by nails:
Δmass = Fe(before) – Fe(after) = ____ g Fe
2) Moles of Fe:
Δmass of Fe = g Fe 1 mole Fe
55.8g Fe = ___ mol Fe
3) Mass of Cu produced:
(mass of beaker + product) – (mass of beaker) = ___ g Cu
4) Moles of Cu:
Mass Cu produced = g Cu 1 mol Cu
63.5 g Cu = ___ mol Cu
5) Mole Ratio:
___ mol Fe
___ mol Cu
___Fe + ___CuCl2  ___FeCl3 + ___Cu

17. 2 Al + 6 HCl 2 AlCl3 + 3 H2 .87mol ?mol .87mol Al 6mol HCl 2mol Al =
4) Aluminum reacts with HCl to produce aluminum chloride (AlCl3) and hydrogen gas. Write a balanced equation for the reaction and calculate the number of moles of HCl required to react with 0.87mol of Al.
2 Al + 6 HCl AlCl3 + 3 H2
.87mol ?mol
.87mol Al 6mol HCl
2mol Al =
5) Glucose (C6H12O6) combines with O2 in the body to produce carbon dioxide and water. Write a balanced equation for this reaction. How many moles of O2 are required to combine with 0.25mol of glucose?

18. 2 Al + 6 HCl 2 AlCl3 + 3 H2 .87mol ?mol .87mol Al 6mol HCl 2mol Al =
4) Aluminum reacts with HCl to produce aluminum chloride (AlCl3) and hydrogen gas. Write a balanced equation for the reaction and calculate the number of moles of HCl required to react with 0.87mol of Al.
2 Al + 6 HCl AlCl3 + 3 H2
.87mol ?mol
.87mol Al 6mol HCl
2mol Al =
5) Glucose (C6H12O6) combines with O2 in the body to produce carbon dioxide and water. Write a balanced equation for this reaction. How many moles of O2 are required to combine with 0.25mol of glucose?
C6H12O O2 6 CO H2O
.25mol ?mol
.25mol C6H12O6 6molHCl
1mol CHO =

19. 6) Determine the mass of lithium hydroxide produced when 0
6) Determine the mass of lithium hydroxide produced when 0.38g of lithium nitride reacts with water according to the following equation: Li3N + 3 H2O NH LiOH
7) What mass of sodium chloride is produced when chloride reacts
with .029g of sodium iodine?

20. .38g Li3N 1mol Li3N 3mol LiOH 24.0g LiOH
6) Determine the mass of lithium hydroxide produced when 0.38g of lithium nitride reacts with water according to the following equation: Li3N + 3 H2O NH LiOH
.38g Li3N 1mol Li3N 3mol LiOH 24.0g LiOH
35.0g Li3N 1mol Li3N 1mol LiOH =
7) What mass of sodium chloride is produced when chloride reacts
with .029g of sodium iodine?

21. .38g Li3N 1mol Li3N 3mol LiOH 24.0g LiOH
6) Determine the mass of lithium hydroxide produced when 0.38g of lithium nitride reacts with water according to the following equation: Li3N + 3 H2O NH LiOH
.38g Li3N 1mol Li3N 3mol LiOH 24.0g LiOH
35.0g Li3N 1mol Li3N 1mol LiOH =
7) What mass of sodium chloride is produced when chloride reacts
with .029g of sodium iodine?
Cl2 + 2 NaI NaCl + I2
.29g NaI 1 mol NaI mol NaCl g NaCl
150.0g NaI 2 mol NaI mol NaCl =

22. 8) Determine the mass of carbon dioxide produced when 0.85g of butane
Reacts with oxygen according to :
2 C4H O CO H2O
9) Determine the mass of antimony produced when 0.46g of antimony (III) oxide reacts with carbon according to the following equation:
Sb2O C Sb + 3 CO

23. 8) Determine the mass of carbon dioxide produced when 0.85g of butane
Reacts with oxygen according to :
2 C4H O CO H2O
0.85g C4H10 1mol C4H10 8mol CO g CO2
58.0g C4H10 2mol C4H10 1mol CO2
= _____g CO2
9) Determine the mass of antimony produced when 0.46g of antimony (III) oxide reacts with carbon according to the following equation:
Sb2O C Sb + 3 CO

24. 8) Determine the mass of carbon dioxide produced when 0.85g of butane
Reacts with oxygen according to :
2 C4H O CO H2O
0.85g C4H10 1mol C4H10 8mol CO g CO2
58.0g C4H10 2mol C4H10 1mol CO2
= _____g CO2
9) Determine the mass of antimony produced when 0.46g of antimony (III) oxide reacts with carbon according to the following equation:
Sb2O C Sb + 3 CO
.46g Sb2O3 1 mol Sb2O3 2 mol Sb g Sb
291.6g Sb2O3 1 mol Sb2O3 1 mol Sb =

25. 10) What mass of hydrogen peroxide (H2O2) must decompose to produce
0.77g of water?
H2O2  H2O O2
11) What mass of carbon monoxide must react with oxygen to produce 0.69g of carbon dioxide?

26. H2O2  H2O + O2 0.77g H2O 1 mol H2O 2 mol H2O2 34.0g H2O2
10) What mass of hydrogen peroxide (H2O2) must decompose to produce
0.77g of water?
H2O2  H2O O2
0.77g H2O 1 mol H2O 2 mol H2O g H2O2
18.0g H2O 2 mol H2O 1 mol H2O = ____g H2O2
11) What mass of carbon monoxide must react with oxygen to produce 0.69g of carbon dioxide?

27. CO + O2  CO2 0.69 CO2 1 mol CO2 2 mol CO 28.0g CO
10) What mass of hydrogen peroxide (H2O2) must decompose to produce
0.77g of water?
H2O2  H2O O2
0.77g H2O 1 mol H2O 2 mol H2O g H2O2
18.0g H2O 2 mol H2O 1 mol H2O = ____g H2O2
11) What mass of carbon monoxide must react with oxygen to produce 0.69g of carbon dioxide?
CO O2  CO2
0.69 CO2 1 mol CO mol CO g CO
44.0g CO mol CO mol CO =

28. CaC2 + H2O Ca(OH)2 + C2H2 __O3 __O2
12) Determine the mass of calcium hydroxide produced when calcium carbide
reacts with 3.64g of water according to the following equation:
CaC H2O Ca(OH) C2H2
13) How many grams of ozone (O3) must produce 0.87g of oxygen?
__O __O2

29. .64g H2O 1 mol H2O 1 mol Ca(OH)2 74.1g Ca(OH)2
12) Determine the mass of calcium hydroxide produced when calcium carbide
reacts with 3.64g of water according to the following equation:
CaC H2O Ca(OH) C2H2
.64g H2O 1 mol H2O 1 mol Ca(OH) g Ca(OH)2
18.0 g H2O 2 mol H2O mol Ca(OH)2 =
Ca(OH)2
13) How many grams of ozone (O3) must produce 0.87g of oxygen?
__O __O2

30. .64g H2O 1 mol H2O 1 mol Ca(OH)2 74.1g Ca(OH)2
12) Determine the mass of calcium hydroxide produced when calcium carbide
reacts with 3.64g of water according to the following equation:
CaC H2O Ca(OH) C2H2
.64g H2O 1 mol H2O 1 mol Ca(OH) g Ca(OH)2
18.0 g H2O 2 mol H2O mol Ca(OH)2 =
Ca(OH)2
13) How many grams of ozone (O3) must produce 0.87g of oxygen?
2 O O2
.87g O mol O mol O g O3
32.0g O mol O mol O3 =

31. Lab12.1 Mass of a Product
- Lab requires 2 days, we will go over the rest of HW#2 on Day 2
- Lab due in 3 school days

32. Ch12.3 – Mass Volume Discuss Lab12.1 (Last slide)
Ex1) How many molecules of oxygen are produced when 29.2g of water
is decomposed?
Ex2) Assuming STP, how many liters of oxygen are needed to produce 19.8 L of SO3?
Ex3) How many mls of nitrogen dioxide are produced when 3.4 ml of oxygen
react with an excess of nitrogen monoxide? Assume STP.

33. Ex1) How many molecules of oxygen are produced when 29.2g of water
is decomposed?
2 H2O H2(g) + O2(g)
Ex2) Assuming STP, how many liters of oxygen are needed to produce 19.8 L of SO3?
2 SO2 + O SO3
Ex3) How many mls of nitrogen dioxide are produced when 3.4 ml of oxygen
react with an excess of nitrogen monoxide? Assume STP.
O NO NO2
Ch12 HW#3 14

34. Lab 12.1 Quantitative Analysis
Data Analysis
1) Mass of Fe lost by nails:
Δmass = Fe(before) – Fe(after) = ____ g Fe
2) Moles of Fe:
Δmass of Fe = g Fe 1 mole Fe
55.8g Fe = ___ mol Fe
3) Mass of Cu produced:
(mass of beaker + product) – (mass of beaker) = ___ g Cu
4) Moles of Cu:
Mass Cu produced = g Cu 1 mol Cu
63.5 g Cu = ___ mol Cu
5) Mole Ratio:
___ mol Fe
___ mol Cu
___Fe + ___CuCl2  ___FeCl3 + ___Cu

35. a) b) c) Ch12 HW#3 14 Sn(s) + 2 HF(g) SnF2 + H2(g) a) ? L 9.40 L
b) L ? molecules
c) x1024 molecules ?g a) b) c)

36. 9.40L H2 1 mol H2 2 mol HF 22.4L HF 22.4L H2 1 mol H2 1 mol HF = b) c)
Sn(s) HF(g) SnF H2(g)
a) ? L L
b) L ? molecules
c) x1024 molecules ?g
9.40L H2 1 mol H mol HF 22.4L HF
22.4L H mol H mol HF = b) c)

37. 20.0 L HF 1 mol HF 1 mol H2 6.02x1023 molecules H2
Sn(s) HF(g) SnF H2(g)
a) ? L L
b) L ? molecules
c) x1024 molecules ?g
9.40L H2 1 mol H mol HF 22.4L HF
22.4L H mol H mol HF =
20.0 L HF 1 mol HF mol H x1023 molecules H2
22.4L HF mol HF 1 mol H2 = c)

38. 20.0 L HF 1 mol HF 1 mol H2 6.02x1023 molecules H2
Sn(s) HF(g) SnF H2(g)
a) ? L L
b) L ? molecules
c) x1024 molecules ?g
9.40L H2 1 mol H mol HF 22.4L HF
22.4L H mol H mol HF =
20.0 L HF 1 mol HF mol H x1023 molecules H2
22.4L HF mol HF 1 mol H2 =
7.42x1024
molecules HF 1 mol HF 1 mol SnF g SnF2
6.02x mol HF mol SnF2
molecules HF =

39. Ch12.4 More Conversions Ch12 HW#4 15 – 20 Discuss Lab12.2 (next slide)
g of potassium reacts with water to produce potassium hydroxide
and hydrogen gas. How many liters would the hydrogen gas occupy at STP?
16. If 30.2 of aluminum react with HCL to produce aluminum chloride
and hydrogen gas, how many liters of hydrogen are produced at STP?

40. Lab12.2 – Hydrated Crystals
1. Mass of the crucible (cool) ________ g
 2. Add about 3 g of MgSO4 hydrated crystals to the crucible, and measure the mass
to the nearest 0.01 g.
Mass of the crucible & MgSO4 hydrated crystals ________ g
 3. Calculate the exact mass of the MgSO4 hydrated crystals.
Mass of the MgSO4 hydrated crystals ________ g
 4. Begin heating slowly. Increase the heat until you have heated the crucible strongly
for about 10 minutes.
5. Remove the crucible from the triangle support, let it cool in a desiccator,
and measure the mass.
Reheat with a hot flame for a few minutes, cool and measure the mass again.
If the mass is different from that found in Step 5, continue to heat and measure
until a constant mass is attained.

41. 1. Mass of the crucible (cool) ________ g
2. Mass of the crucible & MgSO4 hydrated crystals ________ g
3. Mass of the MgSO4 hydrated crystals ________ g
6. Mass of the crucible and anhydrous MgSO4. ________ g
7. Mass of the anhydrous MgSO4 ________ g
8. Subtract the mass of the MgSO4 hydrated crystals minus the mass of the anhydrous salt
to find the mass of water evaporated from the original MgSO4 hydrated crystals.
Mass of H2O evaporated ________ g
 9. Calculate the number of moles of anhydrous salt and of water in order to come up with
a mole ratio for the MgSO4 hydrated crystals.
  Anhydrous:
  _____g MgSO4 | mole MgSO4 = moles MgSO4
| g MgSO4
H2O:
_____g H2O | mole H2O = moles H2O
| g H2O
MgSO4, H2O ratio: MgSO H2O

42. 15. 20.0g of potassium reacts with water to produce potassium hydroxide
and hydrogen gas. How many liters would the hydrogen gas occupy at STP?
K H2O KOH H2
16. If 30.2 of aluminum react with HCL to produce aluminum chloride
and hydrogen gas, how many liters of hydrogen are produced at STP?
Al HCl AlCl H2

43. 17. How many liters of HCL are produced by the reaction of 5
17. How many liters of HCL are produced by the reaction of 5.7L of hydrogen
with an equal amount of chlorine?
18. How many liters of hydrogen are required to react with 0.45 mol of oxygen
to produce water?

44. 17. How many liters of HCL are produced by the reaction of 5
17. How many liters of HCL are produced by the reaction of 5.7L of hydrogen
with an equal amount of chlorine?
H Cl HCl
18. How many liters of hydrogen are required to react with 0.45 mol of oxygen
to produce water?
H O H2O
Ch12 HW#4 19,20 for HW

45. S + O2 SO2 Zn + Cl2 ZnCl2 Ch12 HW#4 15-20
19. How many liters of SO2 are produced from the reaction of sulfur
with 26.9L of oxygen?
S O SO2
20. How many grams of zinc chloride will be produced if zinc is allowed to react
with 16.8L of chlorine at STP?
Zn Cl ZnCl2

46. 19. How many liters of SO2 are produced from the reaction of sulfur
with 26.9L of oxygen?
S O SO2
26.9L O mol O mol SO L SO2
22.4L O2 1 mol O mol SO2 =
20. How many grams of zinc chloride will be produced if zinc is allowed to react
with 16.8L of chlorine at STP?
Zn Cl ZnCl2

47. 16.8L Cl2 1 mol Cl2 1 mol ZnCl2 136.4g ZnCl2
19. How many liters of SO2 are produced from the reaction of sulfur
with 26.9L of oxygen?
S O SO2
26.9L O mol O mol SO L SO2
22.4L O2 1 mol O mol SO2 =
20. How many grams of zinc chloride will be produced if zinc is allowed to react
with 16.8L of chlorine at STP?
Zn Cl ZnCl2
16.8L Cl2 1 mol Cl2 1 mol ZnCl g ZnCl2
22.4L Cl2 1 mol Cl mol ZnCl =

48. Ch12 Mid Chapter Review
1. In Lab12.1 you reacted 2 iron nails with copper (II) chloride. If the nails massed
at 4.25g, and there was enough CuCl2 to completely dissolve the nails,
what mass of copper would be produced?
___Fe + ___CuCl2  ___Cu + ___FeCl3
2. In ch11, magnesium reacted with carbon dioxide to produce magnesium oxide,
carbon, and lots of bright light! How many molecules of carbon dioxide are required
to react with 2.50g of Mg?

49. 3. If lead wasn’t so dangerous for the environment, we would decompose
3.00g of PbCO3.Pb(OH)2 to obtain CO2. What volume should be produced?
2 PbCO3.Pb(OH)2  3PbO + H2O + 2 CO2

50. Ch12 MCR HW 1 – 3
1. If only 1.00g of the iron nails actually dissolved, what mass of copper
would be produced?
2 Fe CuCl FeCl Cu
2. How many molecules of carbon dioxide are required to react with
12.04x1023 atoms of Mg?
2 Mg CO MgO C

51. 1.00g Fe 1 mol Fe 3 mol Cu 63.5g Cu 55.8g Fe 2 mol Fe 1 mol Cu =
Ch12 MCR HW 1 – 3
1. If only 1.00g of the iron nails actually dissolved, what mass of copper
would be produced?
2 Fe CuCl FeCl Cu
1.00g Fe 1 mol Fe 3 mol Cu g Cu
55.8g Fe 2 mol Fe 1 mol Cu =
2. How many molecules of carbon dioxide are required to react with
12.04x1023 atoms of Mg?
2 Mg CO MgO C

52. atoms Mg 1 mol Mg 1 mol CO2 molecules CO2
Ch12 MCR HW 1 – 3
1. If only 1.00g of the iron nails actually dissolved, what mass of copper
would be produced?
2 Fe CuCl FeCl Cu
1.00g Fe 1 mol Fe 3 mol Cu g Cu
55.8g Fe 2 mol Fe 1 mol Cu =
2. How many molecules of carbon dioxide are required to react with
12.04x1023 atoms of Mg?
2 Mg CO MgO C
12.04x x1023
atoms Mg 1 mol Mg 1 mol CO2 molecules CO2
6.02x mol CO2 1 mol CO =
atoms Mg molecules CO2

53. 3. What volumes of CO2 should be produced if 4
3. What volumes of CO2 should be produced if 4.00 g of lead carbonate decompose?
2PbCO3 Pb(OH) PbO H2O CO2

54. 4.00g 2PbCO3 1 mol 2PbCO3 2 mol Co2 22.4L CO2
3. What volumes of CO2 should be produced if 4.00 g of lead carbonate decompose?
2PbCO3 Pb(OH) PbO H2O CO2
4.00g 2PbCO3 1 mol 2PbCO mol Co L CO2
775.6g 2PbCO3 1 mol 2PbCO3 1 mol CO2 =

55. Ch12.5 – Limiting Reactants
Cookie recipe: To make 1 dozen cookies, need 2 eggs, 1 cup sugar.
I have 10 eggs and 3 cups of sugar, how many dozens?
Ex 1) What is the max # of grams of Cu2S that can be formed when 80.0g of Cu
react with 25.0g of S? And, which of them was the limiting reactant?
2 Cu S Cu2S

56. 80g 2 Sg ? g 80.0g Cu 1 mol Cu 1 mol Cu2S 159.1g Cu2S
Cookie recipe: To make 1 dozen cookies, need 2 eggs, 1 cup sugar.
I have 10 eggs and 3 cups of sugar, how many dozens?
Ex 1) What is the max # of grams of Cu2S that can be formed when 80.0g of Cu
react with 25.0g of S? And, which of them was the limiting reactant?
2 Cu S Cu2S
80g Sg ? g
80.0g Cu 1 mol Cu 1 mol Cu2S g Cu2S
63.5g Cu 2 mol Cu mol Cu2S = 100.2g Cu2S
25.0g S 1 mol S 1 mol Cu2S g Cu2S
32.1g S mol S 1 mol Cu2S = 124g Cu2S
= 127.0
= Cu is the Limiting
159.1 g/mol Reactant Ch12 HW#5

57. Ch12 HW#5
21. C2H5OH + O CO2 + H2O; 60 grams C2H5OH, 26L O2 at STP
22. N2 + O NO; 30 grams N2, 30 grams O2

58. 23. CO + H CH3OH; 25 grams CO, 10.0g H2

59. 24. 2 Al + 3 I AlI3; grams Al, 200.0g I2.
25. Ca(OH)2 + HBr CaBr2 + H2O; 80.0 grams Ca(OH)2 75.0g HBr.

60. 24. 2 Al + 3 I AlI3; grams Al, 200.0g I2.
150.0g Al 1 mol Al 2 mol AlI g AlI3
27.0g Al 2 mol Al mol AlI3 =
200.0g I2 1 mol I mol AlI g AlI3
253.8g I mol I mol AlI =
25. Ca(OH)2 + HBr CaBr2 + H2O; 80.0 grams Ca(OH)2 75.0g HBr.

61. 24. 2 Al + 3 I AlI3; grams Al, 200.0g I2.
150.0g Al 1 mol Al 2 mol AlI g AlI3
27.0g Al 2 mol Al mol AlI3 =
200.0g I2 1 mol I mol AlI g AlI3
253.8g I mol I mol AlI =
25. Ca(OH)2 + HBr CaBr2 + H2O; 80.0 grams Ca(OH)2 75.0g HBr.
80.0g Ca(OH)2 1 mol Ca(OH)2 1 mol CaBr g CaBr2
74.1g Ca(OH)2 1 mol Ca(OH)2 1 mol CaBr2 =
75g HBr 1 mol HBr 1 mol CaBr g CaBr2
80.9g HBr 2 mol HBr mol CaBr2 =

62. Ch12.6 More Limiting Reactants Ch12 HW#6 26-29
26. Cr + H3PO CrPO4 + H2; given 50.0 g Cr and
35.0g H3PO4, how many grams of H2 will be produced?
27. C6H O CO H2O; given 75 grams C6H14 and
35.2 L O2 at STP, how many liters of CO2 will be produced?

63. 26. Cr + H3PO4 CrPO4 + H2; given 50.0 g Cr and
35.0g H3PO4, how many grams of H2 will be produced?
50g Cr 1 mol Cr 3 mol H2 2.0g H2
52.0g Cr 2 mol Cr 1 mol H2 =
35g H3PO mol H3PO mol H g H2
98.0g H3PO mol H3PO mol H2 =
27. C6H O CO H2O; given 75 grams C6H14 and
35.2 L O2 at STP, how many liters of CO2 will be produced?

64. 26. Cr + H3PO4 CrPO4 + H2; given 50.0 g Cr and
35.0g H3PO4, how many grams of H2 will be produced?
50g Cr 1 mol Cr 3 mol H2 2.0g H2
52.0g Cr 2 mol Cr 1 mol H2 =
35g H3PO mol H3PO mol H g H2
98.0g H3PO mol H3PO mol H2 =
27. C6H O CO H2O; given 75 grams C6H14 and
35.2 L O2 at STP, how many liters of CO2 will be produced?
75g C6H mol C6H mol CO L CO2
86.0g C6H mol C6H mol CO2 =
35.2 L O mol O mol CO L CO2
22.4 L O mol O mol CO2 =

65. CaCl2 + Na2CO3  CaCO3 + NaCl Cr + Cl2  CrCl3
28) When 65.14g of CaCl2 reacts with 74.68g of NA2CO3, they produce CaCO3
and how many grams of NaCl?
CaCl Na2CO3  CaCO NaCl
29) If 4.1g of Cr is heated with 9.3g of Cl2 what mass of CrCl3 will be produced?
Cr + Cl2  CrCl3

66. 65.14g CaCl2 1 mol CaCl2 2 mol NaCl 58.5 g NaCl
28) When 65.14g of CaCl2 reacts with 74.68g of NA2CO3, they produce CaCO3
and how many grams of NaCl?
CaCl Na2CO3  CaCO NaCl
65.14g CaCl2 1 mol CaCl mol NaCl g NaCl
111.1g CaCl mol CaCl mol NaCl =
74.68g Na2CO mol Na2CO mol NaCl g NaCl
106.0g Na2CO mol Na2CO mol NaCl =
29) If 4.1g of Cr is heated with 9.3g of Cl2 what mass of CrCl3 will be produced?
Cr + Cl2  CrCl3

67. 65.14g CaCl2 1 mol CaCl2 2 mol NaCl 58.5 g NaCl
28) When 65.14g of CaCl2 reacts with 74.68g of NA2CO3, they produce CaCO3
and how many grams of NaCl?
CaCl Na2CO3  CaCO NaCl
65.14g CaCl2 1 mol CaCl mol NaCl g NaCl
111.1g CaCl mol CaCl mol NaCl =
74.68g Na2CO mol Na2CO mol NaCl g NaCl
106.0g Na2CO mol Na2CO mol NaCl =
29) If 4.1g of Cr is heated with 9.3g of Cl2 what mass of CrCl3 will be produced?
Cr + Cl2  CrCl3
4.1g Cr mol Cr mol CrCl g CrCl3
52.0g Cr 2 mol Cr mol CrCl3 =
9.3g Cl mol Cl mol CrCl g CrCl3
71.0 g Cl mol Cl mol CrCl3 =

68. Ch12.7 Percent Yield Ch12 HW#7 30 -33
30. What is the percent yield if 4.65 g of copper is produced
when 1.87 g of aluminum reacts with excess copper (II) sulfate?
2Al(s) + 3 CuSO4(aq)  Al2(SO4)3(aq) + 3Cu(s)

69. 31. Heating an ore of antimony, Sb2S3, in the presence of iron gives
the element antimony and iron(II) sulfide.
Sb2S3(s) + 3Fe(s)  2Sb(s) + 3FeS(s)
When 15.0 g of Sb2S3 reacts with an excess of Fe,
9.84 g of Sb is produced. What is the percent yield of this reaction?

70. 32. Identify the limiting reactant when 4.687 g of SF4
reacts with g of I2O5 to produce IF5 and SO2.

71. 33. When 50.0 g of silicon dioxide is heated with an excess of carbon,
32.2 g of silicon carbide is produced.
SiO2(s) + 3 C(s)  SiC(s) + 2 CO(g)
What is the percent yield of this reaction?

72. __C + __SO2 __CS2 +__CO Ch12 Rev
1) Carbon disulfide is an important industrial solvent. It is prepared by the
reaction of coke with sulfur dioxide.
__C + __SO __CS2 +__CO
How many moles of CS2 form when 2.7 moles of C react?
2) Methanol, CH3OH, is used in the production of many chemicals. It is made
by reacting carbon monoxide and hydrogen at high temps and pressure.
How many moles of carbon monoxide are needed to produce 360 g CH3OH?
CO + 2H CH3OH

73. 4 Zn + 10 HNO3 4 Zn(NO3)2 + NH4NO3 + 3 H2O
3) The reaction of fluorine with ammonia produces dinitrogen tetrafluoride
and hydrogen fluoride. If you have 66.6 g of NH3, how many grams of F2 are
required to complete the reaction?
5 F2 + 2NH N2F4 + 6 HF
4) Nitric acid and zinc react to form zinc nitrate, ammonium nitrate, and water.
4 Zn + 10 HNO Zn(NO3)2 + NH4NO3 + 3 H2O
How many atoms of zinc react with 1.49 g of HNO3 ?

74. 6. Ammonium nitrate decomposes explosively at high temps to form
nitrogen, oxygen, and water vapor. What is the total number of liters of O2
gas formed when 228g of NH4NO3 is decomposed?
NH4NO3  2N2 + 4H2O + O2
7. If 100g of carbon reacts with 85.0g of B2O3, how many grams of B4C3 will
be produced? ___B2O3 + ___C  ___B4C3 + ___CO2