# 8.E: Homework Chapter 8

General Questions

1. If you followed a recipe for pizza that called for one crust, one can of tomatoes, and two cups of cheese, how many pizzas could you make with the following ingredients? Which ingredient limits the quantity of pizzas possible?

4 crusts, 6 cans of tomatoes, and 6 cups of cheese

2. A sandwich recipe calls for 2 slices of bread, 1 piece of cheese, 3 turkey slices, 0.5 avocados, and 1 tbs of mayonnaise. How many sandwiches could you make with 9 slices of bread, 6 pieces of cheese, 15 turkey slices, 3 avocados, and 8 tbs of mayonnaise? Which ingredient is limiting?

Mole-to-Mole Conversions

3. Given the following balanced equation, how many moles of sodium chloride form if 0.14 moles of chlorine and excess sodium react?

2Na(s) + Cl2(g) → 2 NaCl(s)

4. How many moles of hydroxide (H2O2) are required to produce 0.45 moles of oxygen gas?

2H2O2(aq) → O2(g) + 2H2O(l)

5. If 4.5 moles of hydrogen react with excess nitrogen, how many moles of ammonia will be produced?

N2 + 3H2 → 2NH3

6. How much water is produced when 3.7 moles of methane (CH4) react with excess oxygen?

CH4 + 2O2 → CO2 + 2H2O

7. How many moles of sodium chloride will be produced from the neutralization of 2.4 moles of hydrochloric acid?

HCl(aq) +NaOH(aq) → NaCl(aq) + H2O(l)

8. Balance the following chemical equation and determine how many moles of oxygen are require to produce 8.5 moles of nitrogen monoxide.

NH3(g) + O2(g) → NO(g) + H2O(g)

9. Balance the following chemical equation and determine how many moles of ammonia are produced when 5.45 moles of hydrogen gas react with excess nitrogen monoxide.

NO(g) + H2(g) → NH3(g) + H2O(g)

10. Balance the following chemical equation and determine how many moles of product will be produced by each quantity of reactant. Assume that the other reactant is in excess.

A2 + B3 → AB

a. 4.32 moles of A2

b. 2.34 moles of B3

c. 0.8 moles of A2

d. 1.34 moles of B3

11. How many moles of aluminum chloride can be produced in the reaction of 3.45 moles of chlorine with excess aluminum?

2 Al(s) + 3Cl2(g) → 2AlCl3(s)

12. If 6.54 moles of potassium react with excess water, how many moles of potassium hydroxide form? (Hint: check to see if the equation is balanced).

K(s) + H2O(l) → KOH(aq) + H2(g)

13. Balance the following equation and determine how many moles of carbon are needed to produce 6.4 moles of copper (assume excess copper (I) oxide).

Cu2O(s) + C(s) → Cu(s) + CO(g)

14. Balance the following equation. Use it to determine how many moles of CH4 produce 0.34 moles of water vapor (assume excess oxygen).

CH4(g) + O2(g) → CO2(g) + H2O(g)=

Mass-to-Mass Conversions

15. How many grams of sodium chloride form from the reaction of 12.3 g of sodium with excess chlorine?

2Na(s) + Cl2(g) → 2NaCl(s)

16. How many grams of iron (II) chloride are produced when 1.34 g of hydrochloric acid react with excess iron?

Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g)

17. How many grams of CH3OH are needed to produce 34.5 g of carbon dioxide? (Assume excess oxygen).

2 CH3OH(g) + 3O2(g) → 2CO2(g) + 4H2O(l)

18. If 34.68 g of COCl2 decomposes, how many grams of carbon monoxide are produced?

COCl2(g) ® CO (g) + Cl2(g)

19. In the following unbalanced equation, if 0.45 g of chlorine reacts with excess aluminum, how many grams of aluminum chloride are produced?

Al(s) + Cl2(g) ® AlCl3(s)

20. Balance the following equation and use it to determine how many grams of Cu(NO3)2 are needed to produce 12.3 g of CuS (assume excess Na2S).

Na2S(aq) + Cu(NO3)2(aq) ® NaNO3(aq) + CuS(s)

21. How many grams of iron (III) sulfide are produced in the reaction of 3.2 g of iron with excess sulfur?

Fe(s) + S(l) ® Fe2S3(s)

22. How many grams of hydrogen are needed to completely react with 6.7 g of chlorine?

H2(g) + Cl2(g) ® 2HCl(g)

23. How many grams of nitrogen dioxide are needed to completely react with 12.3 g of water?

3NO2(g) + H2O(l) ®2HNO3(aq) + NO(g)

24. How many grams of iron will be dissolved by 23.4 g of sulfuric acid? How much hydrogen gas will be produced in this reaction?

Fe(s) + H2SO4(aq) ® FeSO4(aq) + H2(g)

25. How many grams of glucose (C6H12O6) are produced in the complete reaction of 5.6 g of carbon dioxide with excess water? How many grams of oxygen are produced? (Hint: check if the equation is balanced).

CO2(g) + H2O(l) ® O2(g) + C6H12O6(aq)

26. How many grams of magnesium hydroxide are needed to completely react with 1.3 g of hydrochloric acid? How many grams of water are produced? How many grams of magnesium chloride are produced?

Mg(OH)2(aq) + 2HCl(aq) ® 2H2O(l) + MgCl2(aq)

Limiting Reactant, Theoretical Yield, and Percent Yield

27. For the following reaction, given the initial quantities of each reaction.  Which is the limiting reactant? How many moles of product are produced?

3.4 moles K

1.4 moles Cl2

2K(s) + Cl2(g) ® 2KCl(s)

28. Given the initial amounts, which is the limiting reactant? How many grams of the excess reactant remain?

4.5 moles Mn

3.2 moles O2

2Mn(s) + 3O2(g) ® 2MnO3(s)

29. Based on the initial quantities given, which is the limiting reactant? How many grams of each product will be produced based on this?

12.3 g NaOH

11.9 g HCl

NaOH(aq) + HCl(aq) ® H2O(l) + NaCl(aq)

30. Which reactant is the limiting reactant based on the initial quantities given? What is the theoretical yield of the product in grams?

2.1 moles H2

3.4 moles O2

2H2(g) + O2(g) ® 2H2O(g)

31. Which is the limiting reactant based on the initial quantities?

0.56 mol Al, 0.67 mol Fe2O3

2Al(s) + Fe2O3(s) ® Al2O3(s) +2Fe(l)

32. Balance the following equation. Which reactant limits the reaction based on the initial amounts given? How many moles of carbon dioxide can be produced based on the limiting reactant? How many moles of the excess reactant remain?

1.2 moles C3H8

2.0 moles O2

C3H8(g) + O2(g) ® CO2(g) + H2O(g)

33. Which reactant is limiting based on the amounts provided?

1.4 g Mg

2.4 g O2

2Mg(s) + O2(g) ® 2MgO(s)

34. Using the initial quantities for each reactant and the final quantity of nitrogen monoxide produced (actual yield), determine the limiting reactant, the theoretical yield and the percent yield.

54.8 g ammonia

29.8 g oxygen

12.4 g nitrogen monoxide

4NH3(g) + 5O2(g) ® 4 NO2(g) +6H2O(g)

35. Using the initial quantities for each reactant and the final quantity of hydrochloric acid produced (actual yield), determine the limiting reactant, the theoretical yield and the percent yield.

34.67 g hydrogen

21.88 g chlorine

12.34 g hydrochloric acid

H2(g) + Cl2(g) ® 2HCl(g)

36. Balance the following equation. Use it along with the initial quantities provided to determine the limiting reactant. How many moles of the other reactant remains? What is the theoretical yield in moles?

3.5 mol A

2.5 mol B3

A + B3 ® A2B

37. Balance the following equation. 34.5 g of AB (molar mass 46.7 g/mol) react with 45.6 g of C2 (molar mass 34.5 g/mol) and 23.1 g of (AB)2C (molar mass 116.2 g/mol) are collected. What is the limiting reactant? How many grams of the excess reactant remain?  What is the theoretical yield?

AB + C2 ® (AB)2C

38. 34.76 g of methane reacts in a container with 23.4 g of oxygen, and 12.3 g of carbon dioxide are produced. Which reactant is limiting? What is the theoretical yield of carbon dioxide? What is the percent yield of carbon dioxide?

CH4 + O2 ® CO2 + H2O

39. Find the limiting reactant for each set of initial conditions for the following unbalanced equation.

C6H12O6 + O2 ® CO2 + H2O

a.       2.1 mol C6H12O6, 10.5 mol O2

b.       0.34 mol C6H12O6, 0.45 mol O2

c. 23.4 g C6H12O6, 13.5 g O2

45.654 g C6H12O6, 56.7 g O2

40. 23.4 g Hg(OH)2 react completely with 34.5 g H3PO4. Determine what mass of each reactant and each product remain when the reaction is complete.

3Hg(OH)2 + 2H3PO4 ® Hg3(PO4)2 + 6H2O

41. 3.4 moles of tin(IV) oxide react completely with 5.6 moles of hydrogen. Determine what mass of each reactant and each product remain when the reaction is complete.

SnO2 + H2 ® Sn + H2O

Challenge Problems

42. Gas grills burn propane in order to cook food. How many grams of oxygen are needed to combust a 1.00 L container of propane (C3H8)? (The density of liquid propane is 0.5005 g/mL).

43. Plants take in carbon dioxide and water to produce glucose (C6H12O6) and oxygen gas through the process of photosynthesis. How many grams of glucose can a plant produce if it absorbs 34.5 g of water along with excess carbon dioxide? (Hint: write a balanced chemical equation for the process of photosynthesis.)

44. When iron is left unprotected, such as a nail exposed to the elements, it will develop a red-brown rust coating that weakens the structure of the nail. This coating is the result of the reaction between the iron and oxygen in the air (an oxidation reaction). If a 2.8 g nail (made of solid iron) is left outside, how many grams of iron (III) oxide (rust) will accumulate on the outside of the nail?

45. You can make a volcano by combining vinegar and baking soda. Undergoing a double displacement reaction, the two recombine to form carbon dioxide gas and water. Use the following equation and initial quantities to determine the limiting reactant, the theoretical yield in grams (of each product), and the percent yield (for each product).

HC2H3O2(aq)+ NaHCO3(aq)→ NaC2H3O2(aq)+ H2O(l) + CO2(g)

0.89 g HC2H3O2, 0.99 g NaHCO3

0.42 g CO2, 0.12 g H2O, 0.87 g NaC2H3O2

46. Potassium chloride, a common table salt substitute, can be made from the reaction of hydrochloric acid and potassium hydroxide. How many grams of potassium chloride can be produced by the complete reaction of 34.5 g of hydrochloric acid?

47. Magnesium hydroxide is a common ingredient in antacids. The neutralization of hydrochloric acid in the stomach by magnesium hydroxide is a double displacement reaction. How many grams of magnesium hydroxide are required to neutralize 4.5 g of hydrochloric acid?