STOICHIOMETRY PRACTICE

1. The reaction between potassium chlorate and red phosphorus takes place when you strike a match on a matchbox. If you were to react 52.9 grams of potassium chlorate with excess red phosphorus, what mass of tetraphosphorus decaoxide could be produced?

KClO3(s) + P4(s) P4O10(s) + KCl(s) (unbalanced)

2. Elemental sulfur occurs as octatomic molecules, S8. What mass (g) of fluorine gas is needed to react completely with 17.8 grams of sulfur to form sulfur hexafluoride?

3. The combustion of butane, C4H10, produces carbon dioxide and water. When one sample of butane was burned, 4.46 grams of water was formed. How many grams of oxygen gas were consumed?

4. Barium sulfate is made by the following reaction.

Ba(NO3)2(aq) + Na2SO4(aq) BaSO4(s) + 2NaNO3(aq)

An experiment was begun with 75.00 grams of Ba(NO3)2 and an excess of Na2SO4. After collecting and drying the product, 64.45 grams of BaSO4 was obtained. Calculate the theoretical yield and percentage yield of BaSO4.

5. A solution containing 18.0 grams of AgNO3 was mixed with a solution containing 32.4 grams of FeCl3. How many grams of which reactant remains after the reaction is over?

6. Acrylonitrile (C3H3N) is the starting material for many synthetic carpets and fabrics. It is produced by the following reaction.

2C3H6(g) + 2NH3(g) +3O2(g) 2C3H3N(g) + 6H2O(g)

If 15.0 grams of C3H6, 10.0 grams of O2, and 5.00 grams of NH3 are reacted, what mass of acrylonitrile can be produced, assuming 100% yield?

7. When 78.0 grams of aluminum hydroxide reacts with 49.0 grams of sulfuric acid, what mass of water is produced? (NO CALCULATOR)

2Al(OH)3(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 6H2O(l)

(A) 18.0 g

(B) 36.0 g

(C) 54.0 g

(D) 127 g

8. What mass of aluminum is required if 40.0 grams of iron (III) oxide is to be completely consumed as shown in the following reaction? (NO CALCULATOR)

Fe2O3(s) + 2Al(s) 2Fe(l) + Al2O3(s)

(A) 13.5 g

(B) 27.0 g

(C) 40.0 g

(D) 67.0 g

9. Which of the following reaction mixtures would produce the greatest amount of product, assuming all went to completion? Each involves the reaction symbolized by the equation:

N2(g) + 3H2(g) 2NH3(g)

(A) 2 mol N2 and 4 mol H2

(B) 1 mol N2 and 5 mol H2

(C) 4 mol N2 and 2 mol H2

(D) 5 mol N2 and 1 mol H2

10. Considering the reaction represented above, where the color red represents oxygen and the color blue represents nitrogen, what is the balanced equation for this reaction, and what is the limiting reactant?

11. The reaction of an element X with element Y is represented in the diagram above. Which of the equations best describes this reaction?

(A) 3X + 8Y X3Y8

(B) 3X + 6Y X3Y6

(C) X + 2Y XY2

(D) 3X + 8Y 3XY2 + 2Y

12. Considering the mixture above, where the big blue balls are N2 and the small white balls are H2, assuming the reaction produces ammonia and goes to completion, draw a representation of the product mixture.