Question 1

A compound of bromine and fluorine is used to make UF6, which is an important chemical in processing and reprocessing of nuclear fuel. The compound contains 58.37 mass percent bromine. Determine its empirical formula.

Accepted Answer

A)   BrF
B)   BrF2
C)   Br2F3
D)   Br3F
E)   BrF3F) A) and D)
G) C) and D)

Question 2

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

Accepted Answer

A)   469.73 g/mol
B)   283.89 g/mol
C)   190.97 g/mol
D)   139.88 g/mol
E)   94.97 g/molF) B) and E)
G) C) and D)

Question 3

Balance the following equation: 
B2O3(s)  + HF(l)   BF3(g)  + H2O(l)

Accepted Answer

A)   B2O3(s)  + 6HF(l)   2BF3(g)  + 3H2O(l) 
B)   B2O3(s)  + H6F6(l)   B2F6(g)  + H6O3(l) 
C)   B2O3(s)  + 2HF(l)   2BF3(g)  + H2O(l) 
D)   B2O3(s)  + 3HF(l)   2BF3(g)  + 3H2O(l) 
E)   B2O3(s)  + 6HF(l)   2BF3(g)  + 6H2O(l) F) A) and E)
G) B) and C)

Question 4

Which of the following samples has the most moles of the compound?

Accepted Answer

A)   50.0 g of Li2O
B)   75.0 g of CaO
C)   200.0 g of Fe2O3
D)   50.0 g of CO2
E)   100.0 g of SO3F) B) and C)
G) B) and E)

Question 5

Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula.

Accepted Answer

A)   HNO
B)   H2NO2
C)   HN6O16
D)   HN16O7
E)   H2NO3F) C) and D)
G) C) and E)

Question 6

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) F) B) and E)
G) A) and E)

Question 7

Alkanes are compounds of carbon and hydrogen with the general formula CnH2n+2. An alkane component of gasoline has a molar mass of between 125 and 130 g/mol. What is the value of n for this alkane?

Accepted Answer

A)   4
B)   9
C)   10
D)   13
E)   14F) A) and D)
G) A) and C)

Question 8

Aluminum oxide (used as an adsorbent or a catalyst for organic reactions)  forms when aluminum reacts with oxygen. 4Al(s)  + 3O2(g)   2Al2O3(s) 
A mixture of 82.49 g of aluminum ( 2(g)   2Al2O3(s)  A mixture of 82.49 g of aluminum (   = 26.98 g/mol)  and 117.65 g of oxygen (   = 32.00 g/mol)  is allowed to react. What mass of aluminum oxide (   = 101.96 g/mol)  can be formed? A)  155.8 g B)  200.2 g C)  249.9 g D)  311.7 g E)  374.9 g" class="answers-bank-image d-inline" rel="preload" > = 26.98 g/mol)  and 117.65 g of oxygen ( 2(g)   2Al2O3(s)  A mixture of 82.49 g of aluminum (   = 26.98 g/mol)  and 117.65 g of oxygen (   = 32.00 g/mol)  is allowed to react. What mass of aluminum oxide (   = 101.96 g/mol)  can be formed? A)  155.8 g B)  200.2 g C)  249.9 g D)  311.7 g E)  374.9 g" class="answers-bank-image d-inline" rel="preload" > = 32.00 g/mol)  is allowed to react. What mass of aluminum oxide ( 2(g)   2Al2O3(s)  A mixture of 82.49 g of aluminum (   = 26.98 g/mol)  and 117.65 g of oxygen (   = 32.00 g/mol)  is allowed to react. What mass of aluminum oxide (   = 101.96 g/mol)  can be formed? A)  155.8 g B)  200.2 g C)  249.9 g D)  311.7 g E)  374.9 g" class="answers-bank-image d-inline" rel="preload" > = 101.96 g/mol)  can be formed?

Accepted Answer

A)   155.8 g
B)   200.2 g
C)   249.9 g
D)   311.7 g
E)   374.9 gF) A) and B)
G) C) and D)

Question 9

The formula CH3O0.5 is an example of an empirical formula.

Accepted Answer

A) True 
 B)False

Question 10

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)   Cr2SF) A) and D)
G) D) and E)

Question 11

Gadolinium oxide, a colorless powder which absorbs carbon dioxide from the air, contains 86.76 mass % Gd. Determine its empirical formula.

Accepted Answer

A)   Gd2O3
B)   Gd3O2
C)   Gd3O4
D)   Gd4O3
E)   GdOF) A) and C)
G) A) and B)

Question 12

Constitutional (structural) isomers have the same empirical formula but different molecular formulas.

Accepted Answer

A) True 
 B)False

Question 13

Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride?

Accepted Answer

A)   43.3 g
B)   62.3 g
C)   74.5 g
D)   92.9 g
E)   107 gF) B) and D)
G) B) and C)

Question 14

Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis) . Al(s)  + Br2(l)   Al2Br6(s)  [unbalanced]
How many moles of Al are needed to form 2.43 mol of Al2Br6?

Accepted Answer

A)   7.29 mol
B)   4.86 mol
C)   2.43 mol
D)   1.62 mol
E)   1.22 molF) B) and D)
G) A) and E)

Question 15

How many grams of sodium fluoride (used in water fluoridation and manufacture of insecticides)  are needed to form 485 g of sulfur tetrafluoride? 
3SCl2(l)  + 4NaF(s)   SF4(g)  + S2Cl2(l)  + 4NaCl(s)

Accepted Answer

A)   1940 g
B)   1510 g
C)   754 g
D)   205 g
E)   51.3 gF) D) and E)
G) A) and B)

Question 16

Determine the percent composition of potassium dichromate, K2Cr2O7.

Accepted Answer

A)   17.5% K, 46.6% Cr, 35.9% O
B)   29.8% K, 39.7% Cr, 30.5% O
C)   36.5% K, 48.6% Cr, 14.9% O
D)   37.2% K, 24.7% Cr, 38.1% O
E)   none of the aboveF) C) and E)
G) A) and C)

Question 17

Consider the balanced equation:
Al2S3(s) + 6H2O(l) F1F1F1S1F1F1F10 2Al(OH)3(s) + 3H2S(g)
If 15.0g of aluminum sulfide and 10.0g of water are allowed to react as above, and assuming a complete reaction
a. by calculation, find out which is the limiting reagent.
b. calculate the maximum mass of H2S which can be formed from these reagents.
c. calculate the mass of excess reagent remaining after the reaction is complete.

Accepted Answer

a. Water is the limi...

Question 18

Aluminum metal reacts with chlorine gas to form solid aluminum trichloride, AlCl3. What mass of chlorine gas is needed to react completely with 163 g of aluminum?

Accepted Answer

A)   214 g
B)   245 g
C)   321 g
D)   489 g
E)   643 gF) A) and E)
G) D) and E)

Question 19

Calcium fluoride, CaF2, is a source of fluorine and is used to fluoridate drinking water. Calculate its molar mass.

Accepted Answer

A)   118.15 g/mol
B)   99.15 g/mol
C)   78.07 g/mol
D)   59.08 g/mol
E)   50.01 g/molF) D) and E)
G) C) and E)

Question 20

Aluminum reacts with oxygen to produce aluminum oxide which can be used as an adsorbent, desiccant, or catalyst for organic reactions. 4Al(s)  + 3O2(g)   2Al2O3(s) 
A mixture of 82.49 g of aluminum ( 2(g)   2Al2O3(s)  A mixture of 82.49 g of aluminum (   = 26.98 g/mol)  and 117.65 g of oxygen (   = 32.00 g/mol)  is allowed to react. Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete. A)  Oxygen is the limiting reactant; 19.81 g of aluminum remain. B)  Oxygen is the limiting reactant; 35.16 g of aluminum remain. C)  Aluminum is the limiting reactant; 16.70 g of oxygen remain. D)  Aluminum is the limiting reactant; 35.16 g of oxygen remain. E)  Aluminum is the limiting reactant; 44.24 g of oxygen remain." class="answers-bank-image d-inline" rel="preload" > = 26.98 g/mol)  and 117.65 g of oxygen ( 2(g)   2Al2O3(s)  A mixture of 82.49 g of aluminum (   = 26.98 g/mol)  and 117.65 g of oxygen (   = 32.00 g/mol)  is allowed to react. Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete. A)  Oxygen is the limiting reactant; 19.81 g of aluminum remain. B)  Oxygen is the limiting reactant; 35.16 g of aluminum remain. C)  Aluminum is the limiting reactant; 16.70 g of oxygen remain. D)  Aluminum is the limiting reactant; 35.16 g of oxygen remain. E)  Aluminum is the limiting reactant; 44.24 g of oxygen remain." class="answers-bank-image d-inline" rel="preload" > = 32.00 g/mol)  is allowed to react. Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete.

Accepted Answer

A)   Oxygen is the limiting reactant; 19.81 g of aluminum remain.
B)   Oxygen is the limiting reactant; 35.16 g of aluminum remain.
C)   Aluminum is the limiting reactant; 16.70 g of oxygen remain.
D)   Aluminum is the limiting reactant; 35.16 g of oxygen remain.
E)   Aluminum is the limiting reactant; 44.24 g of oxygen remain.F) B) and E)
G) A) and E)

Exam 3: Stoichiometry of Formulas and Equations

Aluminum metal reacts with chlorine gas to form solid aluminum trichloride, AlCl₃. What mass of chlorine gas is needed to react completely with 163 g of aluminum?

Correct Answer
verified

Alkanes are compounds of carbon and hydrogen with the general formula C_nH₂_n₊₂. An alkane component of gasoline has a molar mass of between 125 and 130 g/mol. What is the value of n for this alkane?

Correct Answer
verified

Constitutional (structural) isomers have the same empirical formula but different molecular formulas.

Correct Answer
verified

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

Correct Answer
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Determine the percent composition of potassium dichromate, K₂Cr₂O₇.

Correct Answer
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A compound of bromine and fluorine is used to make UF₆, which is an important chemical in processing and reprocessing of nuclear fuel. The compound contains 58.37 mass percent bromine. Determine its empirical formula.

Correct Answer
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Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula.

Correct Answer
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Correct Answer
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Gadolinium oxide, a colorless powder which absorbs carbon dioxide from the air, contains 86.76 mass % Gd. Determine its empirical formula.

Correct Answer
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Correct Answer
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a. Water is the limi...
View Answer

Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis) . Al(s) + Br₂(l)  Al₂Br₆(s) [unbalanced] How many moles of Al are needed to form 2.43 mol of Al₂Br₆?

Correct Answer
verified

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

Correct Answer
verified

Which of the following samples has the most moles of the compound?

Correct Answer
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Correct Answer
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Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride?

Correct Answer
verified

Calcium fluoride, CaF₂, is a source of fluorine and is used to fluoridate drinking water. Calculate its molar mass.

Correct Answer
verified

Balance the following equation: B₂O₃(s) + HF(l)  BF₃(g) + H₂O(l)

Correct Answer
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How many grams of sodium fluoride (used in water fluoridation and manufacture of insecticides) are needed to form 485 g of sulfur tetrafluoride? 3SCl₂(l) + 4NaF(s)  SF₄(g) + S₂Cl₂(l) + 4NaCl(s)

Correct Answer
verified

The formula CH₃O_0.5 is an example of an empirical formula.

Correct Answer
verified

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

Correct Answer
verified

Exam 3: Stoichiometry of Formulas and Equations

Aluminum metal reacts with chlorine gas to form solid aluminum trichloride, AlCl3. What mass of chlorine gas is needed to react completely with 163 g of aluminum?

Correct AnswerverifiedShow Answer

Alkanes are compounds of carbon and hydrogen with the general formula CnH2n+2. An alkane component of gasoline has a molar mass of between 125 and 130 g/mol. What is the value of n for this alkane?

Correct AnswerverifiedShow Answer

Constitutional (structural) isomers have the same empirical formula but different molecular formulas.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Determine the percent composition of potassium dichromate, K2Cr2O7.

Correct AnswerverifiedShow Answer

A compound of bromine and fluorine is used to make UF6, which is an important chemical in processing and reprocessing of nuclear fuel. The compound contains 58.37 mass percent bromine. Determine its empirical formula.

Correct AnswerverifiedShow Answer

Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Gadolinium oxide, a colorless powder which absorbs carbon dioxide from the air, contains 86.76 mass % Gd. Determine its empirical formula.

Correct AnswerverifiedShow Answer

Correct Answerverifieda. Water is the limi...View AnswerShow Answer

Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis) . Al(s) + Br2(l)  Al2Br6(s) [unbalanced] How many moles of Al are needed to form 2.43 mol of Al2Br6?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following samples has the most moles of the compound?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride?

Correct AnswerverifiedShow Answer

Calcium fluoride, CaF2, is a source of fluorine and is used to fluoridate drinking water. Calculate its molar mass.

Correct AnswerverifiedShow Answer

Balance the following equation: B2O3(s) + HF(l)  BF3(g) + H2O(l)

Correct AnswerverifiedShow Answer

How many grams of sodium fluoride (used in water fluoridation and manufacture of insecticides) are needed to form 485 g of sulfur tetrafluoride? 3SCl2(l) + 4NaF(s)  SF4(g) + S2Cl2(l) + 4NaCl(s)

Correct AnswerverifiedShow Answer

The formula CH3O0.5 is an example of an empirical formula.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Aluminum metal reacts with chlorine gas to form solid aluminum trichloride, AlCl₃. What mass of chlorine gas is needed to react completely with 163 g of aluminum?

Correct Answer
verified

Alkanes are compounds of carbon and hydrogen with the general formula C_nH₂_n₊₂. An alkane component of gasoline has a molar mass of between 125 and 130 g/mol. What is the value of n for this alkane?

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

Determine the percent composition of potassium dichromate, K₂Cr₂O₇.

Correct Answer
verified

A compound of bromine and fluorine is used to make UF₆, which is an important chemical in processing and reprocessing of nuclear fuel. The compound contains 58.37 mass percent bromine. Determine its empirical formula.

Correct Answer
verified

Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
a. Water is the limi...
View Answer

Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis) . Al(s) + Br₂(l)  Al₂Br₆(s) [unbalanced] How many moles of Al are needed to form 2.43 mol of Al₂Br₆?

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Calcium fluoride, CaF₂, is a source of fluorine and is used to fluoridate drinking water. Calculate its molar mass.

Correct Answer
verified

Balance the following equation: B₂O₃(s) + HF(l)  BF₃(g) + H₂O(l)

Correct Answer
verified

How many grams of sodium fluoride (used in water fluoridation and manufacture of insecticides) are needed to form 485 g of sulfur tetrafluoride? 3SCl₂(l) + 4NaF(s)  SF₄(g) + S₂Cl₂(l) + 4NaCl(s)

Correct Answer
verified

The formula CH₃O_0.5 is an example of an empirical formula.

Correct Answer
verified

Correct Answer
verified