Question 1

A student weighed 0.550 g of lithium chloride,LiCl,to use in a reaction.How many moles is this?

Accepted Answer

A)  77.08
B)  42.39
C)  23.31
D)  5.11
E)  0.0130 E

Question 2

The formula weight of copper(II) chloride is ________ g.

Accepted Answer

A)  98.90
B)  133.00
C)  134.45
D)  162.53
E)  197.80 C

Question 3

A solution containing 145.0 g AgNO3 is mixed with a CaCl2 solution and 98.4 of AgCl is recovered.Calculate the % yield of the reaction.

Accepted Answer

A)  40.16%
B)  61.11%
C)  61.99%
D)  80.44%
E)  161.3%

Question 4

Which statement based on the mole concept is not correct?

Accepted Answer

A)  The molar mass of a diatomic element is its atomic weight times two.
B)  The number of atoms in one mole of platinum is the same as the number of atoms in one mole of uranium.
C)  One mole of sodium chloride,NaCl,contains the same number of ions as one mole of calcium sulfate,CaSO4.
D)  One mole of methane,CH4,contains the same number of atoms as one mole of carbon dioxide,CO2.
E)  One mole of bromine,Br2,contains the same number of molecules as one mole of propane,C3H8.

Question 5

The following equation represents the formation of nitrogen dioxide,a major component of smog,
2 NO + O2 → 2 NO2
If 0.68 mole of NO is reacted with 0.79 mole of O2 to produce NO2,the limiting reactant is ________.

Accepted Answer

A)  both NO and O2
B)  NO
C)  O2
D)  NO2

Question 6

The number of grams in 0.350 mol of Na is ________.

Accepted Answer

A)  0.350
B)  8.05
C)  11.0
D)  23.0
E)  65.7

Question 7

50.0 g of Cl2 contains ________ mol Cl2.

Accepted Answer

A)  50.0
B)  1775
C)  0.705
D)  1.41
E)  4.24 × 1023

Question 8

In the balanced reaction shown,the mole ratio of Fe2S3 to O2 is
Fe2S3 + 4 O2 → 2 FeO + 3 SO2

Accepted Answer

A)  5 to 5.
B)  1 to 4.
C)  4 to 1.
D)  1 to 2.
E)  4 to 3.

Question 9

Match the following.
-The molar mass of C15H32

Accepted Answer

A)  208.2 g
B)  212.4 g
C)  219 g
D)  225 g

Question 10

105 g of MgCl2 contains ________ mol MgCl2.

Accepted Answer

A)  105
B)  6.62 × 1023
C)  1.10
D)  1.76
E)  1.06 × 1024

Question 11

The molar mass of butane,C4H10,is ________ grams.

Accepted Answer

A)  22.01
B)  49.05
C)  52.08
D)  58.12
E)  68.24

Question 12

How many molecules are present in 4.25 mol of CCl4?

Accepted Answer

A)  9.26 × 1025
B)  2.56 × 1024
C)  653.69
D)  153.81
E)  36.91

Question 13

In the reaction 2 C + O2 → 2 CO,how many moles of carbon are needed to produce 66.0 g of carbon monoxide?

Accepted Answer

A)  0.424
B)  1.18
C)  2.36
D)  4.71
E)  28.3

Question 14

The molar mass of Fe(OH) 3 is ________ g.

Accepted Answer

A)  72.86
B)  74.88
C)  89.87
D)  104.86
E)  106.87

Question 15

How many grams of C will be consumed when 5.00 grams of Na2SO4 react according to the balanced reaction shown?
Na2SO4 + 2 C → Na2S + 2 CO2

Accepted Answer

A)  0.038 g
B)  0.211 g
C)  0.844 g
D)  1.69 g
E)  17.1 g

Question 16

Which statement concerning the mole is not correct?

Accepted Answer

A)  The molar mass of any compound is equal to its molecular weight in grams.
B)  A mole of metal contains NA atoms of that metal.
C)  A mole of any compound contains one mole of each kind of atom found in that compound.
D)  A mole of a diatomic element contains 2 × NA moles of atoms of the element.
E)  All of these statements are correct.

Question 17

How many moles of CO2 are produced when 2.5 moles of O2 react according to the following equation?
C3H5 + 5 O2 → 3 CO2 + 4 H2O

Accepted Answer

A)  1.5
B)  3
C)  5
D)  6
E)  18

Question 18

The molecular weight of PCl3 is ________ amu.

Accepted Answer

A)  66.42
B)  136.00
C)  137.33
D)  139.00
E)  199.26

Question 19

The percentage yield of a reaction can best be described as the ________ times 100%.

Accepted Answer

A)  amount of product you could make if the reaction went to completion
B)  total amount of materials involved in a reaction
C)  amount of desired product divided by the amount of unwanted product
D)  amount of product obtained divided by the maximum possible amount of product
E)  amount of reactants left over divided by the original amounts

Question 20

How many moles of NaHCO3 are present in a 2.00 g sample?

Accepted Answer

A)  2.38 × 10-2 mol
B)  1.27 × 10-2 mol
C)  2.00 mol
D)  85.0 mol
E)  168 mol A

Exam 6: Chemical Reactions: Mole and Mass Relationships

A student weighed 0.550 g of lithium chloride,LiCl,to use in a reaction.How many moles is this?

Correct AnswerverifiedE

The formula weight of copper(II) chloride is ________ g.

Correct AnswerverifiedC

A solution containing 145.0 g AgNO3 is mixed with a CaCl2 solution and 98.4 of AgCl is recovered.Calculate the % yield of the reaction.

Correct AnswerverifiedShow Answer

Which statement based on the mole concept is not correct?

Correct AnswerverifiedShow Answer

The following equation represents the formation of nitrogen dioxide,a major component of smog, 2 NO + O2 → 2 NO2 If 0.68 mole of NO is reacted with 0.79 mole of O2 to produce NO2,the limiting reactant is ________.

Correct AnswerverifiedShow Answer

The number of grams in 0.350 mol of Na is ________.

Correct AnswerverifiedShow Answer

50.0 g of Cl2 contains ________ mol Cl2.

Correct AnswerverifiedShow Answer

In the balanced reaction shown,the mole ratio of Fe2S3 to O2 is Fe2S3 + 4 O2 → 2 FeO + 3 SO2

Correct AnswerverifiedShow Answer

Match the following. -The molar mass of C15H32

Correct AnswerverifiedShow Answer

105 g of MgCl2 contains ________ mol MgCl2.

Correct AnswerverifiedShow Answer

The molar mass of butane,C4H10,is ________ grams.

Correct AnswerverifiedShow Answer

How many molecules are present in 4.25 mol of CCl4?

Correct AnswerverifiedShow Answer

In the reaction 2 C + O2 → 2 CO,how many moles of carbon are needed to produce 66.0 g of carbon monoxide?

Correct AnswerverifiedShow Answer

The molar mass of Fe(OH) 3 is ________ g.

Correct AnswerverifiedShow Answer

How many grams of C will be consumed when 5.00 grams of Na2SO4 react according to the balanced reaction shown? Na2SO4 + 2 C → Na2S + 2 CO2

Correct AnswerverifiedShow Answer

Which statement concerning the mole is not correct?

Correct AnswerverifiedShow Answer

How many moles of CO2 are produced when 2.5 moles of O2 react according to the following equation? C3H5 + 5 O2 → 3 CO2 + 4 H2O

Correct AnswerverifiedShow Answer

The molecular weight of PCl3 is ________ amu.

Correct AnswerverifiedShow Answer

The percentage yield of a reaction can best be described as the ________ times 100%.

Correct AnswerverifiedShow Answer

How many moles of NaHCO3 are present in a 2.00 g sample?

Correct AnswerverifiedA

Correct Answer
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E

Correct Answer
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C

A solution containing 145.0 g AgNO₃ is mixed with a CaCl₂ solution and 98.4 of AgCl is recovered.Calculate the % yield of the reaction.

Correct Answer
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Correct Answer
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The following equation represents the formation of nitrogen dioxide,a major component of smog, 2 NO + O₂ → 2 NO₂ If 0.68 mole of NO is reacted with 0.79 mole of O₂ to produce NO₂,the limiting reactant is ________.

Correct Answer
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Correct Answer
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50.0 g of Cl₂ contains ________ mol Cl₂.

Correct Answer
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In the balanced reaction shown,the mole ratio of Fe₂S₃ to O₂ is Fe₂S₃+ 4 O₂ → 2 FeO + 3 SO₂

Correct Answer
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Match the following. -The molar mass of C₁₅H₃₂

Correct Answer
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105 g of MgCl₂ contains ________ mol MgCl₂.

Correct Answer
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The molar mass of butane,C₄H₁₀,is ________ grams.

Correct Answer
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How many molecules are present in 4.25 mol of CCl₄?

Correct Answer
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In the reaction 2 C + O₂ → 2 CO,how many moles of carbon are needed to produce 66.0 g of carbon monoxide?

Correct Answer
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The molar mass of Fe(OH) ₃ is ________ g.

Correct Answer
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How many grams of C will be consumed when 5.00 grams of Na₂SO₄ react according to the balanced reaction shown? Na₂SO₄+ 2 C → Na₂S + 2 CO₂

Correct Answer
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Correct Answer
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How many moles of CO₂ are produced when 2.5 moles of O₂ react according to the following equation? C₃H₅ + 5 O₂ → 3 CO₂ + 4 H₂O

Correct Answer
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The molecular weight of PCl₃ is ________ amu.

Correct Answer
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Correct Answer
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How many moles of NaHCO₃ are present in a 2.00 g sample?

Correct Answer
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A