1. STOICHIOMETRY PRACTICE

2. 1. When solid aluminum chloride is heated at high temperatures, solid aluminum and chlorine gas are produced.
a. Write and balance the reaction that occurs.
on the top of your white board.

3. 1. When solid aluminum chloride is heated at high temperatures, solid aluminum and chlorine gas are produced.
a. Write and balance the reaction that occurs.
2 AlCl3 → 2Al + 3Cl2

4. c. What mass of aluminum chloride must decompose in order to form 10
c. What mass of aluminum chloride must decompose in order to form 10.25g of aluminum?

5. c. What mass of aluminum chloride must decompose in order to form 10
c. What mass of aluminum chloride must decompose in order to form 10.25g of aluminum?
10.25g Al 1 mole Al moles AlCl g AlCl3 =
26.98 g Al mole Al mole AlCl3
50.65g AlCl3

6. d. What mass of aluminum will be produced if 13
d. What mass of aluminum will be produced if 13.5g of chlorine are produced?

7. d. What mass of aluminum will be produced if 13
d. What mass of aluminum will be produced if 13.5g of chlorine are produced?
13.5 g Cl2 1mole Cl2 2moles Al g Al = 3.42 g Al
70.90 g Cl2 3 moles Cl2 1mole

8. e. What mass of aluminum will be produced if 20
e. What mass of aluminum will be produced if 20.5g of chlorine are produced?

9. 20.5g Cl2 1 mole Cl2 2moles Al 26.98g Al = 5.20 g Al
e. What mass of aluminum will be produced if 20.5g of chlorine are produced?
20.5g Cl2 1 mole Cl2 2moles Al g Al = 5.20 g Al
70.90 g Cl moles Cl2 1mole Al

10. f. How many atoms of aluminum will be produced if 20
f. How many atoms of aluminum will be produced if 20.5g of chlorine are produced?

11. f. How many atoms of aluminum will be produced if 20
f. How many atoms of aluminum will be produced if 20.5g of chlorine are produced?
20.5g Cl2 1 mole Cl2 2moles Al x 1023
70.90 g Cl2 3moles Cl2 1mole Al
=1.16 x 1023 atoms Al

12. g. What mass of chlorine will be produced if 5
g. What mass of chlorine will be produced if 5.00g of aluminum chloride decompose?

13. g. What mass of chlorine will be produced if 5
g. What mass of chlorine will be produced if 5.00g of aluminum chloride decompose?
5.00g AlCl mole AlCl moles Cl g Cl =
133.33g AlCl3 2 moles AlCl mole Cl2
  3.99 g Cl2

14. 2. When flourine is bubbled through a hydrobromic acid solution, bromine and hydrofluoric acid are formed.
a. Write the balanced equation for the reaction.
b. What type of reaction is this?

15. 2. When flourine is bubbled through a hydrobromic acid solution, bromine and hydrofluoric acid are formed.
a. Write the balanced equation for the reaction.
F2 + 2HBr → Br2 + 2HF
b. What type of reaction is this?
Single replacement

16. b. What mass of bromine will be formed if 25
b. What mass of bromine will be formed if 25.0g of fluorine react with excess hydrofluoric acid, and the reaction has an 83.4% yield?

17. b. What mass of bromine will be formed if 25
b. What mass of bromine will be formed if 25.0g of fluorine react with excess hydrofluoric acid and the reaction has an 83.4% yield?
25.0 g F mole F mole Br g Br2 expected g Br2
38.0 g F mole F mole Br g expected
= g Br2

18. 20. 0g of fluorine gas react with excess hydrobromic acid
20.0g of fluorine gas react with excess hydrobromic acid. Determine the mass of hydrofluoric acid formed if the reaction has a 92.7% yield.

19. 20.0g F2 1 mol F2 2 mol HF 20.01g HF expected 92.7g HF formed
c. 20.0g of fluorine gas react with excess hydrobromic acid. Determine the mass of hydrofluoric acid formed if the reaction has a 92.7% yield.
20.0g F mol F mol HF g HF expected 92.7g HF formed
38.00g F mol F mol HF g expected
= 19.5g HF

20. d. What mass of hydrobromic acid must react with excess fluorine in order to form 16.0g of bromine, assuming the reaction has an 85.0% yield?

21. d. What mass of hydrobromic acid must react with excess fluorine in order to form 16.0g of bromine, assuming the reaction has an 85.0% yield?
16.0g Br2 formed 100g Br2 expected 1molBr mol HBr g HBr
85.0g Br2 formed g Br2 1 mole Br mole HBr
= 13.8g HBr

22. e. A student reacts 725mL of fluorine gas with excess hydrobromic acid at STP. The reaction produces 1.10g of hydrofluoric acid. Determine the % yield.

23. e. A student reacts 725mL of fluorine gas with excess hydrobromic acid at STP. The reaction produces 1.10g of hydrofluoric acid. Determine the % yield.
0.725L F molF mol HF g HF = 1.30g HF expected
22.4L F mole F mole HF
% yield = 1.10g HF x 100 = 84.6%
1.30g HF

24. 3. Iron reacts with sulfuric acid to form iron(III) sulfate and hydrogen gas.
a. Write the balanced reaction below.
b. What type of reaction is this?

25. 3. Iron reacts with sulfuric acid to form iron(III) sulfate and hydrogen gas.
a. Write the balanced reaction below.
2Fe + 3H2SO4 → Fe2(SO4)3 + 3H2
b. What type of reaction is this?
Single Replacement

26. c. What mass of iron is needed to react with 10.5g of sulfuric acid?

27. c. What mass of iron is needed to react with 10.5g of sulfuric acid?
10.5 g H2SO mol H2SO moles Fe g Fe =
98.09 g moles H2SO4 1 moles Fe
3.98g Fe

28. d. What mass of iron(III) sulfate will be formed if 5
d. What mass of iron(III) sulfate will be formed if 5.5g of iron react with excess sulfuric acid, and the reaction has a 94.0% yield?

29. d. What mass of iron(III) sulfate will be formed if 5
d. What mass of iron(III) sulfate will be formed if 5.5g of iron react with excess sulfuric acid, and the reaction has a 94.0% yield?
5.5g Fe 1mol Fe mol Fe2(SO4) g expected g formed g mole Fe mol Fe2(SO4) g expected
= 19g Fe2(SO4)3

30. What mass of sulfuric acid is needed to form 18
What mass of sulfuric acid is needed to form 18.0L of hydrogen gas, at STP, if the reaction has a 75.0% yield?

31. What mass of sulfuric acid is needed to form 18
What mass of sulfuric acid is needed to form 18.0L of hydrogen gas, at STP, if the reaction has a 75.0% yield?
18.0L H L H2 expected 1 mol H2SO mol g
75.0L formed L H mol H mol H2SO4
= g H2SO4

32. 4. When solid calcium nitride is heated at high temperatures, solid calcium and nitrogen gas are produced. 
a. Write and balance the reaction that occurs.
b. Identify the reaction type.

33. 4. When solid calcium nitride is heated at high temperatures, solid calcium and nitrogen gas are produced. 
a. Write and balance the reaction that occurs.
Ca3N2 → 3Ca + N2
b. Identify the reaction type.
Decomposition

34. c. What mass of calcium nitride must decompose in order to form 10
c. What mass of calcium nitride must decompose in order to form 10.25g of calcium?

35. c. What mass of calcium nitride must decompose in order to form 10
c. What mass of calcium nitride must decompose in order to form 10.25g of calcium?
10.25g Ca 1mol Ca 1mol Ca3N g = 12.6 g Ca3N2
40g mol Ca mol Ca3N2

36. d. What mass of calcium will be produced if 13
d. What mass of calcium will be produced if 13.5g of nitrogen are produced?

37. d. What mass of calcium will be produced if 13
d. What mass of calcium will be produced if 13.5g of nitrogen are produced?
13.5g N2 1mol N2 3mols Ca 40g = 57.9 g Ca
28g mol N mol Ca

38. e. What volume of nitrogen, assuming the reaction is at STP, will be produced if 5.00g of calcium nitride decompose?

39. e. What volume of nitrogen, assuming the reaction is at STP, will be produced if 5.00g of calcium nitride decompose?
5.00g Ca3N2 1mol Ca3N2 1mol N L = .76 L N2
148 g mol Ca3N2 1mol N2