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Chemistry: Stoichiometry: Spring Final 2011: Name________________________

Class #: __________________________ Date: ________________________

Lithium and oxygen react explosively to form lithium oxide. How many moles of lithium oxide will form if 2 moles of lithium react?

a.   ?    3

b.   ?    2

c.   ?    1.5

d.   ?    1

The percentage that compares the actual yield to the theoretical yield is called

e.   ?    percent error

f.   ?    experimental error

g.   ?    percent yield

h.   ?    experimental yield

Carbon disulfide and oxygen react to yield carbon dioxide and sulfur dioxide. If 1 mole of CS2 is combined with 1 mole of oxygen, how many moles of sulfur dioxide are formed?

i.   ?    none

j.   ?    0.667 moles

k.   ?    0.334 moles

l.   ?    1.25 moles

The reactant you run out of first is known as

m.   ?    the absent reactant

n.   ?    the limiting reactant

o.   ?    the excess reactant

p.   ?    the running reactant

Carbon disulfide and oxygen react to yield carbon dioxide and sulfur dioxide. If 1 mole of CS2 is combined with 1 mole of oxygen, how many moles of excess reactant remain?

q.   ?    none

r.   ?    0.667 moles

s.   ?    0.334 moles

t.   ?    1.25 moles

Sulfuric acid reacts with sodium hydroxide to yield sodium sulfate and water. If 37 grams of sulfuric acid react with 30 grams of sodium hydroxide, how many grams of water are produced?

u.   ?    I need a bit more time...

v.   ?    37 grams

w.   ?    14 grams

x.   ?    53 grams

When ammonia reacts with oxygen gas, nitrogen gas and water are formed. If 4 moles of nitrogen gas are produced, how many moles of oxygen were used?

y.   ?    4

z.   ?    6

aa.   ?    2

ab.   ?    3

When the magnesium hydroxide reacts with the hydrochloric acid in your stomach, water and magnesium chloride are produced. What mass of HCl is required to completely react with 3 grams of magnesium chloride?

ac.   ?    4.90 g

ad.   ?    11.5 g

ae.   ?    3.75 g

af.   ?    30.7 g

In an experiment, students determined the theoretical yield to be 20 grams. Their actual yield was 15 grams. What was their percent yield?

ag.   ?    75%

ah.   ?    1.33%

ai.   ?    7.5%

aj.   ?    133%

9. If 16 grams of O2 react with excess C2H6, how many grams of CO2 will be formed? The formula mass of O2 = 32 amu and the formula mass of CO2 = 44 amu. The balanced chemical equation is...

[pic]

|(a) |22 grams |

|(b) |13 grams |

|(c) |9 grams |

|(d) |7 grams |

10. If 64 grams of O2 react with 45 grams of C2H6, how many grams of CO2 will be formed? The formula mass of O2 = 32 amu, C2H6 = 30 and the formula mass of CO2 = 44 amu. The balanced chemical equation is given in the previous problem.

|(a) |132 grams |

|(b) |66 grams |

|(c) |50 grams |

|(d) |44 grams |

11. How many milliliters of 2 M NaCl solution are required to make 1 liter of 0.4 M NaCl solution?

|(a) |5,000 mL |

|(b) |800 mL |

|(c) |200 mL |

|(d) |0.2 mL |

12 If an air bag in a car needs 44.8 L of gas when filled, how many grams of NaN3 are needed to fill the bag with nitrogen gas at standard temperature and pressure? Remember that one mole of any gas will occupy 22.4 L at STP. The balanced chemical is...

[pic]

|(a) |56 grams |

|(b) |87 grams |

|(c) |130 grams |

|(d) |1.3 grams |

13. How many grams of NaOH are needed to make 100 milliliters of a 0.2 molar solution of NaOH?

|(a) |0.02 grams |

|(b) |0.8 grams |

|(c) |20 grams |

|(d) |800 grams |

14. How many grams of NaHCO3 (baking soda) would you need to neutralize 500 mL of battery acid (H2SO4) that has been spilled on your garage floor? Assume that the concentration of the battery acid is 12 molar. The balanced chemical equation is...

[pic]

|(a) |1,008,000 grams |

|(b) |1,008 grams |

|(c) |504 grams |

|(d) |252 grams |

15. When 157.0 grams of CaSO4 are dissolved in enough water to yield a volume of  7.25x102 milliliters of solution. The molarity of this solution will be...

|(a) |0.0016 M |

|(b) |0.837 M |

|(c) |1.15 M |

|(d) |1.59 M |

16. How many grams of carbon are needed to completely react with 75.2 g of SiO2? The balanced chemical equation is...

[pic]

|(a) |3.76 g |

|(b) |15.1 g |

|(c) |36.0 g |

|(d) |45.1 g |

17. How many milliliters of 4.00 M NaOH must be added to 100.0 mL of 0.2000 M H2SO4 solution to completely neutralize the acid? The balanced chemical equation is...

[pic]

|(a) |0.04 mL |

|(b) |5.0 mL |

|(c) |10.0 mL |

|(d) |500 mL |

18. In an acid-base titration, 42.90 mL of 0.825 M H2SO4 was required to neutralize 75.0 mL of NaOH solution. What is the molarity of the NaOH solution? The balanced chemical equation is given in the previous problem.

|(a) |0.0009 M |

|(b) |0.071 M |

|(c) |0.472 M |

|(d) |0.944 M |

19. If you react 1.00 L of ethane at STP with 3.00 L of oxygen at STP, how many grams of carbon dioxide will be formed? One mole of any gas occupies 22.4 L at STP. The balanced chemical equation is...

[pic]

|(a) |1.96 g |

|(b) |3.37 g |

|(c) |3.93 g |

|(d) |5.89 g |

20. What is the percent yield of water if 0.90 g of water is obtained when 29.0 g of butane is burned in excess oxygen? The balanced chemical equation is...

[pic]

|(a) |0.02% |

|(b) |2% |

|(c) |10% |

|(d) |36% |

|21. One of the functions of the catalytic converter in your car is to oxidize carbon monoxide to carbon dioxide. If 15.0 g of |

|carbon monoxide reacts with 9.0 g of oxygen, how many grams of which compound remains unreacted? The balanced chemical equation |

|is... |

|[pic] |

|(a) |0.4 g of oxygen remains unreacted |

|(b) |0.8 g of carbon monoxide remains unreacted |

|(c) |7.1 g of carbon monoxide remains unreacted |

|(d) |8.1 g of oxygen remains unreacted |

22. In order to calculate percent error, you must

ak.   ?    all of the above, then take the most logical number

al.   ?    take the actual yield divided by the theoretical yield, and multiply by 100

am.   ?    take the theoreticall yield divided by the actual yield, and multiply by 100

an.   ?    take the actual yield minus the theoretical yield, divide by the theoretical yield, and multiply by 100

When sodium chloride reacts with silver nitrate, silver chloride and sodium nitrate are produced. What mass of silver chloride is produced from 75 grams of silver nitrate?

a.   ?    182 g b.  ?    63.3 g

c.  ?     126.5 g d.  ?    33.5 g

• What is the molarity of a solution in which 2 moles of solute are dissolved in 8 liters of solution?

1.   ?    6 M

2.   ?    16 M

3.   ?    4 M

4.   ?    0.25 M

• What is the molarity of a solution in which 2 moles of solute is dissolved in 500 mL of solution.

1.   ?    0.004 M

2.   ?    4 M

3.   ?    250 M

4.   ?    1000 M

• Calculate the concentration of the following solution in units of molarity, M, moles per liter:

80 grams of NaOH is dissolved in 2 L of solution

1.   ?    1 M NaOH

2.   ?    160 M NaOH

3.   ?    82 M NaOH

4.   ?    40 M NaOH

• What is the molarity of a solution in which 34 grams of ammonia, NH3, is dissolved in 4000 mL of solution?

1.   ?    0.0085 M

2.   ?    117.6 M

3.   ?    0.5 M

4.   ?    8.5 M

• What is the percentage concentration of a solution in which 15 grams of NaCl is dissolved in 3000 mL of solution?

1.   ?    2 % NaCl

2.   ?    0.5 % NaCl

3.   ?    5.0 % NaCl

4.   ?    200 % NaCl

• What is the percentage concentration of a solution in which 90 grams of solute is dissolved in 3 liters of solution?

1.   ?    270%

2.   ?    30%

3.   ?    0.33%

4.   ?    3%

• Calculate the concentration of the following solution in units of percent composition:

100 grams of glucose is dissolved in 1000 mL of solution

1.   ?    100% glucose

2.   ?    100% glucose

3.   ?    0.10% glucose

4.   ?    10% glucose

• What is the percentage concentration of a solution in which 10 grams of carbon dioxide, CO2 is dissolved in 1 liter of solution?

1.   ?    1%

2.   ?    0.1%

3.   ?    10%

4.   ?    1000%

• What two substances are always produced by a neutralization reaction?

1.   ?    water and a base

2.   ?    water and an acid

3.   ?    water and a salt

4.   ?    an acid and a base

1. What is the molarity (moles per liter) of a solution in which 80 grams of sodium hydroxide, NaOH, is dissolved in 1 liter of solution?

Answer: M

2. Calculate the molarity of a solution of potassium fluoride, KF, in which 58 grams of the compound are dissolved in 4 liters of solution.

Answer: M

3. What is the molarity of a solution in which 51 grams of aluminum oxide, Al2O3, is dissolved in 500 mL of solution?

Answer: M

4. A solution with a volume of 0.25 liters contains 10 grams of hydrogen fluoride, HF. What is the molarity of the solution?

Answer: M

5. What is the percent composition of a solution in which 80 grams of sodium hydroxide, NaOH, is dissolved in 1 liter of solution?

Answer: %

6. A solution of sugar contains 35 grams of sucrose, C12H22O11 in 100 mL of solution. What is the percent composition of the solution?

Answer: %

7. What is the percent composition of a solution in which 50 grams of aluminum oxide, Al2O3, is dissolved in 500 mL of solution?

Answer: %

8. What is the percent composition of a solution in which 480 grams of sodium chloride, NaCl, is dissolved in 4 liters of solution.

Answer: %

1. 6.5 grams of aluminum metal reacts with excess hydrochloric acid to produce what mass of hydrogen gas?

2. KClO3 decomposes into KCl and oxygen gas. What mass of oxygen gas can be produced by the decomposition of 200 grams of KClO3?

3. What mass of water vapor is produced by the combustion of 500 grams of C2H6?

4. Na2SIO3 (s) + HF(aq) → H2SiF6 (aq) + NaF(aq) + H2O (l)

a. How many moles of HF are needed to react with 0.300 mol of Na2SiO3?

b. How many grams of NaF form when 0.500 mol of HF reacts with excess Na2SiO3?

c. How many grams of Na2SiO3 can react with 0.800 g of HF?

5. C6H12O6 (aq) → C2H5OH (aq) + CO2 (g)

a. How many moles of CO2 are produced when 0.400 mol of C6H12O6 reacts in this fashion?

b. How many grams of C6H12O6 are needed to form 7.50 g of C2H5OH?

c. How many grams of CO2 form when 7.50 g of C2H5OH are produced?

6. Fe2O3 (s) + CO (g) → Fe(s) + CO2 (g)

a. Calculate the number of grams of CO that can react with 0.150 kg of Fe2O3

b. Calculate the number of grams of Fe and the number of grams of CO2 formed when 0.150 kg of Fe2O3 reacts

7. NaOH (s) + CO2 (g) → Na2CO3 (s) + H2O (l)

a. Which reagent is the limiting reactant when 1.85 mol NaOH and 1.00 mol CO2 are allowed to react?

b. How many moles of Na2CO3 can be produced?

8. C6H6 + Br2 → C6H5Br + HBr

a. What is the theoretical yield of C6H5Br in this reaction when 30.0 g of C6H6 reacts with 65.0 g or Br2?

b. If the actual yield of C6H5Br was 56.7 g, what is the percent yield?

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