Question 1

Magnesium (used in the manufacture of light alloys)  reacts with iron(III)  chloride to form magnesium chloride and iron. 3Mg(s)  + 2FeCl3(s)  → 3MgCl2(s)  + 2Fe(s)  A mixture of 41.0 g of magnesium ( 3(s)  → 3MgCl2(s)  + 2Fe(s)  A mixture of 41.0 g of magnesium (   = 24.31 g/mol)  and 175 g of iron(III)  chloride (   = 162.2 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)  Limiting reactant is Mg; 67 g of FeCl3 remain. B)  Limiting reactant is Mg; 134 g of FeCl3 remain. C)  Limiting reactant is Mg; 104 g of FeCl3 remain. D)  Limiting reactant is FeCl3; 2 g of Mg remain. E)  Limiting reactant is FeCl3; 87 g of Mg remain." class="answers-bank-image d-inline" rel="preload" > = 24.31 g/mol)  and 175 g of iron(III)  chloride ( 3(s)  → 3MgCl2(s)  + 2Fe(s)  A mixture of 41.0 g of magnesium (   = 24.31 g/mol)  and 175 g of iron(III)  chloride (   = 162.2 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)  Limiting reactant is Mg; 67 g of FeCl3 remain. B)  Limiting reactant is Mg; 134 g of FeCl3 remain. C)  Limiting reactant is Mg; 104 g of FeCl3 remain. D)  Limiting reactant is FeCl3; 2 g of Mg remain. E)  Limiting reactant is FeCl3; 87 g of Mg remain." class="answers-bank-image d-inline" rel="preload" > = 162.2 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)   Limiting reactant is Mg; 67 g of FeCl3 remain.
B)   Limiting reactant is Mg; 134 g of FeCl3 remain.
C)   Limiting reactant is Mg; 104 g of FeCl3 remain.
D)   Limiting reactant is FeCl3; 2 g of Mg remain.
E)   Limiting reactant is FeCl3; 87 g of Mg remain.F) A) and D)
G) A) and E)

Question 2

In combustion analysis, the carbon and hydrogen contents of a substance are determined from the CO2 and H2O, respectively, which are collected in the absorbers.

Accepted Answer

A) True 
 B)False

Question 3

How many atoms are in a drop of mercury that has a diameter of 1.0 mm? (Volume of a sphere is 4πr3/3; density of mercury = 13.6 g/cm3)

Accepted Answer

A)   2.1 × 1019
B)   1.7 × 1020
C)   2.1 × 1022
D)   1.7 × 1023
E)   None of these choices are correct.F) B) and C)
G) A) and E) A

Question 4

Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO2 and 0.226 g H2O. If its molar mass is between 158 and 167 g/mol, what is its molecular formula?

Accepted Answer

A)   C4H6O7
B)   C6H8O5
C)   C7H12O4
D)   C4H3O2
E)   C8H6O4F) B) and E)
G) B) and C)

Question 5

Methanol (CH4O)  is converted to bromomethane (CH3Br)  as follows: CH4O + 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)   40.9%
B)   82.6%
C)   100%
D)   121%
E)   245%F) A) and B)
G) B) and E)

Question 6

In combustion analysis, the oxygen content of a substance is equal to the total oxygen in the CO2 and H2O collected in the absorbers.

Accepted Answer

A) True 
 B)False

Question 7

Calculate the molar mass of (NH4) 3AsO4.

Accepted Answer

A)   417.80 g/mol
B)   193.03 g/mol
C)   165.02 g/mol
D)   156.96 g/mol
E)   108.96 g/molF) All of the above
G) A) and E)

Question 8

Magnesium reacts with iron(III)  chloride to form magnesium chloride (which can be used in fireproofing wood and in disinfectants)  and iron. 3Mg(s)  + 2FeCl3(s)  → 3MgCl2(s)  + 2Fe(s) 
A mixture of 41.0 g of magnesium ( 3(s)  → 3MgCl2(s)  + 2Fe(s)  A mixture of 41.0 g of magnesium (   = 24.31 g/mol)  and 175 g of iron(III)  chloride (   = 162.2 g/mol)  is allowed to react. What mass of magnesium chloride = 95.21 g/mol)  is formed? A)  68.5 g MgCl2 B)  77.0 g MgCl2 C)  71.4 g MgCl2 D)  107 g MgCl2 E)  154 g MgCl2" class="answers-bank-image d-inline" rel="preload" > = 24.31 g/mol)  and 175 g of iron(III)  chloride ( 3(s)  → 3MgCl2(s)  + 2Fe(s)  A mixture of 41.0 g of magnesium (   = 24.31 g/mol)  and 175 g of iron(III)  chloride (   = 162.2 g/mol)  is allowed to react. What mass of magnesium chloride = 95.21 g/mol)  is formed? A)  68.5 g MgCl2 B)  77.0 g MgCl2 C)  71.4 g MgCl2 D)  107 g MgCl2 E)  154 g MgCl2" class="answers-bank-image d-inline" rel="preload" > = 162.2 g/mol)  is allowed to react. What mass of magnesium chloride = 95.21 g/mol)  is formed?

Accepted Answer

A)   68.5 g MgCl2
B)   77.0 g MgCl2
C)   71.4 g MgCl2
D)   107 g MgCl2
E)   154 g MgCl2F) A) and E)
G) C) and D)

Question 9

Calculate the molar mass of rubidium carbonate, Rb2CO3.

Accepted Answer

A)   340.43 g/mol
B)   255.00 g/mol
C)   230.94 g/mol
D)   145.47 g/mol
E)   113.48 g/molF) A) and C)
G) A) and E)

Question 10

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) A) and B)
G) A) and C)

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain. Calculate the mass in grams of 3.65 × 1020 molecules of SO3.

Accepted Answer

A)   6.06 × 10-4 g
B)   2.91 × 10-2 g
C)   4.85 × 10-2 g
D)   20.6 g
E)   1650 gF) A) and B)
G) A) and D) C

Question 13

Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO2 and 0.226 g H2O. What is its empirical formula?

Accepted Answer

A)   C2H3O4
B)   C3H4O2
C)   C4H3O2
D)   C5H12O4
E)   C2H2OF) C) and D)
G) B) and C)

Question 14

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 B)
G) A) and C) B

Question 15

What is the mass in grams of 0.250 mol of the common antacid calcium carbonate?

Accepted Answer

A)   4.00 × 102 g
B)   25.0 g
C)   17.0 g
D)   4.00 × 10-2 g
E)   2.50 × 10-3 gF) D) and E)
G) B) and D)

Question 16

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) All of the above
G) B) and D)

Question 17

Aluminum sulfate, Al2(SO4) 3, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molar mass.

Accepted Answer

A)   450.06 g/mol
B)   342.15 g/mol
C)   315.15 g/mol
D)   278.02 g/mol
E)   74.98 g/molF) All of the above
G) B) and D)

Question 18

Hydroxylamine 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)   N2H2O4F) C) and E)
G) A) and E)

Question 19

Balance the following equation: Ca3(PO4) 2(s)  + SiO2(s)  + C(s)  → CaSiO3(s)  + CO(g)  + P4(s)

Accepted Answer

A)   Ca3(PO4) 2(s)  + 3SiO2(s)  + 8C(s)  → 3CaSiO3(s)  + 8CO(g)  + P4(s) 
B)   Ca3(PO4) 2(s)  + 3SiO2(s)  + 14C(s)  → 3CaSiO3(s)  + 14CO(g)  + P4(s) 
C)   Ca3(PO4) 2(s)  + 3SiO2(s)  + 8C(s)  → 3CaSiO3(s)  + 8CO(g)  + 2P4(s) 
D)   2Ca3(PO4) 2(s)  + 6SiO2(s)  + 10C(s)  → 6CaSiO3(s)  + 10CO(g)  + P4(s) 
E)   2Ca3(PO4) 2(s)  + 6SiO2(s)  + 10C(s)  → 6CaSiO3(s)  + 10CO(g)  + 4P4(s) F) A) and B)
G) A) and C)

Question 20

The number of hydrogen atoms in 0.050 mol of C3H8O3 is

Accepted Answer

A)   3.0 × 1022 H atoms.
B)   1.2 × 1023 H atoms.
C)   2.4 × 1023 H atoms.
D)   4.8 × 1023 H atoms.
E)   None of these choices are correct.F) C) and D)
G) A) and E)

Exam 3: Stoichiometry of Formulas and Equations

Correct Answer
verified

In combustion analysis, the carbon and hydrogen contents of a substance are determined from the CO₂ and H₂O, respectively, which are collected in the absorbers.

Correct Answer
verified

How many atoms are in a drop of mercury that has a diameter of 1.0 mm? (Volume of a sphere is 4πr³/3; density of mercury = 13.6 g/cm³)

Correct Answer
verified
A

Correct Answer
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Methanol (CH₄O) is converted to bromomethane (CH₃Br) as follows: CH₄O + 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
verified

In combustion analysis, the oxygen content of a substance is equal to the total oxygen in the CO₂ and H₂O collected in the absorbers.

Correct Answer
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Calculate the molar mass of (NH₄) ₃AsO₄.

Correct Answer
verified

Correct Answer
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Calculate the molar mass of rubidium carbonate, Rb₂CO₃.

Correct Answer
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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

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

Correct Answer
verified

Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain. Calculate the mass in grams of 3.65 × 10²⁰ molecules of SO₃.

Correct Answer
verified
C

Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO₂ and 0.226 g H₂O. What is its empirical formula?

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
B

What is the mass in grams of 0.250 mol of the common antacid calcium carbonate?

Correct Answer
verified

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

Correct Answer
verified

Aluminum sulfate, Al₂(SO₄) ₃, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molar mass.

Correct Answer
verified

Hydroxylamine 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 Answer
verified

Balance the following equation: Ca₃(PO₄) ₂(s) + SiO₂(s) + C(s) → CaSiO₃(s) + CO(g) + P₄(s)

Correct Answer
verified

The number of hydrogen atoms in 0.050 mol of C₃H₈O₃ is

Correct Answer
verified

Exam 3: Stoichiometry of Formulas and Equations

Correct AnswerverifiedShow Answer

In combustion analysis, the carbon and hydrogen contents of a substance are determined from the CO2 and H2O, respectively, which are collected in the absorbers.

Correct AnswerverifiedShow Answer

How many atoms are in a drop of mercury that has a diameter of 1.0 mm? (Volume of a sphere is 4πr3/3; density of mercury = 13.6 g/cm3)

Correct AnswerverifiedA

Correct AnswerverifiedShow Answer

Methanol (CH4O) is converted to bromomethane (CH3Br) as follows: CH4O + 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

In combustion analysis, the oxygen content of a substance is equal to the total oxygen in the CO2 and H2O collected in the absorbers.

Correct AnswerverifiedShow Answer

Calculate the molar mass of (NH4) 3AsO4.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Calculate the molar mass of rubidium carbonate, Rb2CO3.

Correct AnswerverifiedShow 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

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

Correct AnswerverifiedShow Answer

Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain. Calculate the mass in grams of 3.65 × 1020 molecules of SO3.

Correct AnswerverifiedC

Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO2 and 0.226 g H2O. What is its empirical formula?

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 AnswerverifiedB

What is the mass in grams of 0.250 mol of the common antacid calcium carbonate?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Aluminum sulfate, Al2(SO4) 3, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molar mass.

Correct AnswerverifiedShow Answer

Hydroxylamine 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: Ca3(PO4) 2(s) + SiO2(s) + C(s) → CaSiO3(s) + CO(g) + P4(s)

Correct AnswerverifiedShow Answer

The number of hydrogen atoms in 0.050 mol of C3H8O3 is

Correct AnswerverifiedShow Answer

Correct Answer
verified

In combustion analysis, the carbon and hydrogen contents of a substance are determined from the CO₂ and H₂O, respectively, which are collected in the absorbers.

Correct Answer
verified

How many atoms are in a drop of mercury that has a diameter of 1.0 mm? (Volume of a sphere is 4πr³/3; density of mercury = 13.6 g/cm³)

Correct Answer
verified
A

Correct Answer
verified

Methanol (CH₄O) is converted to bromomethane (CH₃Br) as follows: CH₄O + 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
verified

In combustion analysis, the oxygen content of a substance is equal to the total oxygen in the CO₂ and H₂O collected in the absorbers.

Correct Answer
verified

Calculate the molar mass of (NH₄) ₃AsO₄.

Correct Answer
verified

Correct Answer
verified

Calculate the molar mass of rubidium carbonate, Rb₂CO₃.

Correct Answer
verified

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

Correct Answer
verified

Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain. Calculate the mass in grams of 3.65 × 10²⁰ molecules of SO₃.

Correct Answer
verified
C

Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO₂ and 0.226 g H₂O. What is its empirical formula?

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
B

Correct Answer
verified

Correct Answer
verified

Aluminum sulfate, Al₂(SO₄) ₃, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molar mass.

Correct Answer
verified

Correct Answer
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Balance the following equation: Ca₃(PO₄) ₂(s) + SiO₂(s) + C(s) → CaSiO₃(s) + CO(g) + P₄(s)

Correct Answer
verified

The number of hydrogen atoms in 0.050 mol of C₃H₈O₃ is

Correct Answer
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