Question 1

There is only one distinct empirical formula for each compound that exists.

Accepted Answer

A) True 
 B)False

Question 2

What is the empirical formula for a sample containing 81.70% carbon and 18.29% hydrogen?

Accepted Answer

A)  CH
B)  CH3
C)  C2H6
D)  CH4
E)  C3H8

Question 3

The ______________ is defined by the following equation

Accepted Answer

The answer of The ______________ is defined by the following...

Question 4

Balance the following equation: C8H18O3(l) + O2(g) → H2O(g) + CO2(g)

Accepted Answer

A)  C8H18O3(l) + 8O2(g) → 9H2O(g) + 8CO2(g) 
B)  C8H18O3(l) + 11O2(g) → 9H2O(g) + 8CO2(g) 
C)  2C8H18O3(l) + 22O2(g) → 9H2O(g) + 16CO2(g) 
D)  C8H18O3(l) + 13O2(g) → 18H2O(g) + 8CO2(g) 
E)  2C8H18O3(l) + 17O2(g) → 18H2O(g) + 16CO2(g)

Question 5

Balance the following equation: UO2(s) + HF(l) → UF4(s) + H2O(l)

Accepted Answer

A)  UO2(s) + 2HF(l) → UF4(s) + H2O(l) 
B)  UO2(s) + 4HF(l) → UF4(s) + 2H2O(l) 
C)  UO2(s) + H4F4(l) → UF4(s) + H4O2(l) 
D)  UO2(s) + 4HF(l) → UF4(s) + 4H2O(l) 
E)  UO2(s) + 8HF(l) → 2UF4(s) + 4H2O(l)

Question 6

How many grams of calcium metal is required to react with 7.75 g water to produce calcium hydroxide and hydrogen gas?

Accepted Answer

A)  8.62 g
B)  34.5 g
C)  4.31 g
D)  40.1 g
E)  17.2 g

Question 7

A compound containing chromium and silicon contains 73.52 mass percent chromium.Determine its empirical formula.

Accepted Answer

A)  CrSi3
B)  Cr2Si3
C)  Cr3Si
D)  Cr3Si2
E)  Cr4Si3

Question 8

The density of water is 1.00 g/mL at 4°C.How many water molecules are present in 6.25 mL of water at this temperature? (NA = 6.022 × 1023 mol-1)

Accepted Answer

A)  6.27 × 1023 molecules
B)  3.76 × 1024 molecules
C)  2.09 × 1023 molecules
D)  6.02 × 1023 molecules
E)  0.347 molecules

Question 9

Household sugar,sucrose,has the molecular formula C12H22O11.What is the % of carbon in sucrose,by mass?

Accepted Answer

A)  26.7%
B)  33.3%
C)  41.4%
D)  42.1%
E)  51.4%

Question 10

Hydroxyl ammonium nitrate contains 29.17 mass % N,4.20 mass % H,and 66.63 mass % O.If its molar mass is between 94 and 98 g/mol,what is its molecular formula?

Accepted Answer

A)  NH2O5
B)  N2H4O4
C)  N3H3O3
D)  N4H8O2
E)  N2H2O4

Question 11

What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers? ___ Na + ___ H2O → ___ NaOH + ___ H2

Accepted Answer

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

Question 12

Calculate the molecular mass of tetraphosphorus decaoxide,P4O10,a corrosive substance which can be used as a drying agent.

Accepted Answer

A)  469.73 amu
B)  283.88 amu
C)  190.97 amu
D)  139.88 amu
E)  94.97 amu

Question 13

What mass of Cr can be produced by the reaction of 44.1 g of Cr2O3 with 35.0 g of Al according to the following chemical equation? 2Al + Cr2O3 → Al2O3 + 2Cr

Accepted Answer

A)  15.1 g
B)  30.2 g
C)  67.4 g
D)  99.9 g
E)  104 g

Question 14

Tetraphosphorus hexaoxide is formed by the reaction of phosphorus with oxygen gas.If a mixture of 75.3 g of phosphorus and 38.7 g of oxygen produce 43.3 g of P4O6,what is the percent yield for the reaction?

Accepted Answer

A)  57.5%
B)  48.8%
C)  38.0%
D)  89.4%
E)  16.3%

Question 15

If 119.3 g of PCl5 are formed from the reaction of 61.3 g Cl2 with excess PCl3,what is the percent yield? PCl3(g) + Cl2(g) → PCl5(g)

Accepted Answer

A)  94.6%
B)  66.3%
C)  57.3%
D)  51.3%
E)  48.6%

Question 16

What is the coefficient of O2 when the following equation is properly balanced with the smallest set of whole numbers? ___ CH3OH + ___ O2 → ___ CO2 + ___ H2O

Accepted Answer

A)  1
B)  2
C)  3
D)  7
E)  None of these answers is correct.

Question 17

Methanol (CH3OH) is converted to bromomethane (CH3Br) as follows: CH3OH + HBr → CH3Br + H2O
If 12.23 g of bromomethane are produced when 5.00 g of methanol is reacted with excess HBr,what is the percentage yield?

Accepted Answer

A)  12.9%
B)  33.8%
C)  40.9%
D)  59.1%
E)  82.6%

Question 18

If 13.9 g of oxygen react with 33.7 g of calcium to produce calcium oxide,what is the limiting reactant and what mass of calcium oxide is produced?

Accepted Answer

A)  Calcium is the limiting reactant and 47.2 g of calcium oxide are produced
B)  Oxygen is the limiting reactant and 24.4 g of calcium oxide are produced
C)  Calcium is the limiting reactant and 47.20 g of calcium oxide are produced
D)  Oxygen is the limiting reactant and 48.7 g of calcium oxide are produced
E)  Calcium is the limiting reactant and 23.6 g of calcium oxide are produced

Question 19

What mass of sodium fluoride (used in water fluoridation and the manufacture of insecticides) is required to form 485 g of sulfur tetrafluoride? 3SCl2(l) + 4NaF(s) → SF4(g) + S2Cl2(l) + 4NaCl(s)

Accepted Answer

A)  1.94 kg
B)  1.51 kg
C)  754 g
D)  205 g
E)  51.3 g

Question 20

How many moles of ammonia,NH3,are in 13.81 g of NH3?

Accepted Answer

A)  1.234 moles
B)  0.8107 moles
C)  8.316 × 1024 moles
D)  4.881 × 1023 moles
E)  235.3 moles

Exam 3: Stoichiometry Ratios of Combination

What mass of Cr can be produced by the reaction of 44.1 g of Cr2O3 with 35.0 g of Al according to the following chemical equation? 2Al + Cr2O3 → Al2O3 + 2Cr

Correct AnswerverifiedShow Answer

Calculate the molecular mass of tetraphosphorus decaoxide,P4O10,a corrosive substance which can be used as a drying agent.

Correct AnswerverifiedShow Answer

Household sugar,sucrose,has the molecular formula C12H22O11.What is the % of carbon in sucrose,by mass?

Correct AnswerverifiedShow Answer

What is the coefficient of O2 when the following equation is properly balanced with the smallest set of whole numbers? ___ CH3OH + ___ O2 → ___ CO2 + ___ H2O

Correct AnswerverifiedShow Answer

There is only one distinct empirical formula for each compound that exists.

Correct AnswerverifiedShow Answer

If 13.9 g of oxygen react with 33.7 g of calcium to produce calcium oxide,what is the limiting reactant and what mass of calcium oxide is produced?

Correct AnswerverifiedShow Answer

Hydroxyl ammonium nitrate contains 29.17 mass % N,4.20 mass % H,and 66.63 mass % O.If its molar mass is between 94 and 98 g/mol,what is its molecular formula?

Correct AnswerverifiedShow Answer

Balance the following equation: C8H18O3(l) + O2(g) → H2O(g) + CO2(g)

Correct AnswerverifiedShow Answer

How many grams of calcium metal is required to react with 7.75 g water to produce calcium hydroxide and hydrogen gas?

Correct AnswerverifiedShow Answer

Tetraphosphorus hexaoxide is formed by the reaction of phosphorus with oxygen gas.If a mixture of 75.3 g of phosphorus and 38.7 g of oxygen produce 43.3 g of P4O6,what is the percent yield for the reaction?

Correct AnswerverifiedShow Answer

How many moles of ammonia,NH3,are in 13.81 g of NH3?

Correct AnswerverifiedShow Answer

The ______________ is defined by the following equation

Correct AnswerverifiedShow Answer

A compound containing chromium and silicon contains 73.52 mass percent chromium.Determine its empirical formula.

Correct AnswerverifiedShow Answer

If 119.3 g of PCl5 are formed from the reaction of 61.3 g Cl2 with excess PCl3,what is the percent yield? PCl3(g) + Cl2(g) → PCl5(g)

Correct AnswerverifiedShow Answer

What mass of sodium fluoride (used in water fluoridation and the manufacture of insecticides) is required to form 485 g of sulfur tetrafluoride? 3SCl2(l) + 4NaF(s) → SF4(g) + S2Cl2(l) + 4NaCl(s)

Correct AnswerverifiedShow Answer

What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers? ___ Na + ___ H2O → ___ NaOH + ___ H2

Correct AnswerverifiedShow Answer

What is the empirical formula for a sample containing 81.70% carbon and 18.29% hydrogen?

Correct AnswerverifiedShow Answer

The density of water is 1.00 g/mL at 4°C.How many water molecules are present in 6.25 mL of water at this temperature? (NA = 6.022 × 1023 mol-1)

Correct AnswerverifiedShow Answer

Methanol (CH3OH) is converted to bromomethane (CH3Br) as follows: CH3OH + HBr → CH3Br + H2O If 12.23 g of bromomethane are produced when 5.00 g of methanol is reacted with excess HBr,what is the percentage yield?

Correct AnswerverifiedShow Answer

Balance the following equation: UO2(s) + HF(l) → UF4(s) + H2O(l)

Correct AnswerverifiedShow Answer

What mass of Cr can be produced by the reaction of 44.1 g of Cr₂O₃ with 35.0 g of Al according to the following chemical equation? 2Al + Cr₂O₃ → Al₂O₃ + 2Cr

Correct Answer
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Calculate the molecular mass of tetraphosphorus decaoxide,P₄O₁₀,a corrosive substance which can be used as a drying agent.

Correct Answer
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Household sugar,sucrose,has the molecular formula C₁₂H₂₂O₁₁.What is the % of carbon in sucrose,by mass?

Correct Answer
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What is the coefficient of O2 when the following equation is properly balanced with the smallest set of whole numbers? _ CH₃OH + _ O₂ → _ CO₂ + _ H₂O

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Balance the following equation: C₈H₁₈O₃(l) + O₂(g) → H₂O(g) + CO₂(g)

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Tetraphosphorus hexaoxide is formed by the reaction of phosphorus with oxygen gas.If a mixture of 75.3 g of phosphorus and 38.7 g of oxygen produce 43.3 g of P₄O₆,what is the percent yield for the reaction?

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How many moles of ammonia,NH₃,are in 13.81 g of NH₃?

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If 119.3 g of PCl₅ are formed from the reaction of 61.3 g Cl₂ with excess PCl₃,what is the percent yield? PCl₃(g) + Cl₂(g) → PCl₅(g)

Correct Answer
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What mass of sodium fluoride (used in water fluoridation and the manufacture of insecticides) is required to form 485 g of sulfur tetrafluoride? 3SCl₂(l) + 4NaF(s) → SF₄(g) + S₂Cl₂(l) + 4NaCl(s)

Correct Answer
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What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers? _ Na + _ H₂O → _ NaOH + _ H₂

Correct Answer
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The density of water is 1.00 g/mL at 4°C.How many water molecules are present in 6.25 mL of water at this temperature? (N_A = 6.022 × 10²³ mol-1)

Correct Answer
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Methanol (CH₃OH) is converted to bromomethane (CH₃Br) as follows: CH₃OH + HBr → CH₃Br + H₂O If 12.23 g of bromomethane are produced when 5.00 g of methanol is reacted with excess HBr,what is the percentage yield?

Correct Answer
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Balance the following equation: UO₂(s) + HF(l) → UF₄(s) + H₂O(l)

Correct Answer
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