Chapter 9 - Stoichiometry Problems – 35 points total

1. Aluminum Sulfate reacts in a double displacement reaction with Calcium Hydroxide. If you begin with 2.45 g of Aluminum Sulfate, how many grams of Aluminum Hydroxide will be produced? 1.12 g Al(OH)₃

2. Methanol (CH₃OH), burns in a combustion reaction. If you are given 30.9g of methanol to begin your reaction, how many grams of water will be produced? 34.8 g H₂O

3. Use the balanced equation in number 2 to answer this: How many grams of O₂ are required to burn those 30.9 g of methanol? 46.4 g O₂

4. Use the balanced equation in number 2 to answer this: How many grams of CO₂ will be produced from those 30.9 g of methanol? 42.5 g CO₂.

5. Add the mass of the methanol (30.9g) to the mass of oxygen (46.4g).

6. Add the mass of carbon dioxide (42.5 g) to the mass of water (34.8g). Why are the sums the same as those in question #5?

7. Aluminum reacts with Silver Nitrate in a single displacement reaction. If you begin your experiment with a 32.1g piece of aluminum foil, how much silver (+1) (in grams) will be produced? 385 g Ag

8. Use your balanced equation from number 7 to answer this: How many grams of aluminum nitrate will be produced? You can again assume a 32.1 g piece of Al foil. 253 g Al(NO₃)₃

9. Use your balanced equation from number 7 to answer this: How many grams of Silver Nitrate are required to fully react with the 32.1 g piece of aluminum? 606 g AgNO₃

10. Hydrogen gas and oxygen gas are combined in a synthesis reaction. If you begin with 9.00 g of hydrogen, how many grams of the product do you create? 80.2 g H₂O

11. Sodium Bicarbonate (also known as baking soda or by its chemical formula NaHCO₃), reacts with hydrochloric acid (HCl) to produce three products: Salt, Water, and Carbon dioxide. If you begin with 0.25 g of Sodium Bicarbonate, how many grams of salt should be produced? (We will do this experiment in lab!!!!!!!) 0.172 g NaCl

Also do Practice problems #1-2 p. 282, Practice problems 1-3 p. 284, Practice Problems 1-2 p. 285

Practice problems 1-3 p. 287. (remember to write the page number above the problem set)

Stoichiometry with Moles instead of Grams

12. If you have 5.00 moles of hydrogen gas and burn it with oxygen, how many grams of water will be produced? 90.0 g H₂O

13. If you have 3.00 moles of methanol, how many moles of carbon dioxide are produced?

3.00 moles CO₂

14. If you have 3.00 moles of methanol, how many grams of carbon dioxide are produced?

132 grams CO₂

15. If you have 3.00 moles of methanol, how many grams of water are produced?

108 g H₂O

Stoichiometry with Molarity

16. You have 100. mL of a 5.00 M solution of HCl. If you add this to a large chunk of Aluminum, how many grams of Aluminum Chloride would be produced? 22.3 g AlCl₃

17. You have 60.0 mL of a 1.7 x 10^-3M soln. of Copper (II) sulfate. If you add this to a large piece of zinc (+2), how many grams of zinc (II) sulfate will be produced? 0.0165 g ZnSO₄

18. If you have 2.00 L of a 3.1 x 10^-5M soln. of Copper (II) sulfate, and you add it to a large piece of zinc (+2), how many grams of zinc (II) sulfate will be produced? 0.0100 g ZnSO₄

Stoichiometery with Limiting Reagents

Answers should be:

a. Which reactant is in excess

b. Which reactant is the limiting reagent

c. How many grams of the excess reagent is going to be left over

d. How many grams of the underlined product will be produced (in grams).

Problems #19-23 are balanced for you (how nice!) – they might not be on a test, however.

19. If 26.9 g of NO₂ are reacted with 3.55 g of water

3NO₂ + H₂O ----> 2HNO₃ + NO

a. H₂O b. NO₂ c. 0.0413 g H₂O d. 24.6 g HNO₃

20. If 24.8 g of Mg are reacted with 93.5 g of H₂SO₄.

Mg + H₂SO₄ ----> MgSO₄ + H₂

a. Mg b. H₂SO₄ c. 1.62 g Mg d. 115 g MgSO₄

21. If 26.6 g of methane are reacted with 26.6 g of Chlorine.

CH₄ + 4Cl₂ -----> 4HCl + CCl₄

a. CH₄ b. Cl₂ c. 25.1 g CH₄ d. 14.4 g CCl₄

22. If 2.54 g of CaC₂ are reacted with 2.54 g of N₂.

CaC₂ + N₂ -----> CaCN₂ + C

a. N₂ b. CaC₂ c. 1.43 g N₂ d. 3.18 g CaCN₂

23. If 45.3 g of Al are reacted with 16.4 g of MnO.

2Al + 3MnO ------> Al₂O₃ + 3Mn

a. Al b. MnO c. 41.1 g Al d. 7.86 g Al₂O₃

Also, do practice problems 1-2 p. 291

Stoichiometry with Limiting reagents and Molarity

HINT: Your answer to letter “c” must be in grams. Since your solution is in moles, you will need to subtract moles from moles but then convert that answer into grams!

24. You have 2.00 L of a 3.00 M soln. of Copper (II) sulfate. If you add this to 65.4 g of zinc (+2), answer the a, b, c, d questions. (the product: zinc (II) sulfate is “underlined”)

a. CuSO₄ b. Zn c. 5 moles of CuSO₄ or 798 g CuSO₄ d. 161 g of ZnSO₄

25. You have 800. mL of a 5.00 M soln of HCl. If you add this to 10.0 g of aluminum in a single displacement rxn, answer the a, b, c, d questions. (the product: aluminum chloride is “underlined”)

a. HCl b. Al c. 105 g HCl d. 49.4 g AlCl₃

26. You have 400. mL of a 3.00 M soln of HCl. If you add this to 200.0 g of Zinc (+2) in a single displacement rxn, answer the a, b, c, d questions. (the product: zinc (II) chloride is “underlined”)

a. Zn b. HCl c. 161 g Zn d. 81.8 g ZnCl₂