The iodine "clock reaction" involves the following sequence of reactions occurring in a reaction mixture in a single beaker. 1.IO3(aq) + 5I−(aq) + 6H+(aq) → 3I2(aq) + 3H2O(l) 2.I2(aq) + 2S2O32−(aq) → 2I−(aq) + S4O62−aq) The molecular iodine (I2) formed in reaction 1 is immediately used up in reaction 2, so that no iodine accumulates. What is the overall reaction occurring in this experiment?

A) IO 3 −( aq)+ 3I −( aq)+ 2S 2O3 2 − aq)+ 6H+( aq)→ 2I 2( aq)+ S 4O6 2 −( aq)+ 3H 2O( l) B) IO 3( aq)+ 4S 2O3 2 −( aq)+ 6H+( aq)→ I −( aq)+ 2S 4O6 2 −( aq)+ 3H 2O( l) C) IO 3− aq)+ 6S 2O3 2 − aq)+ 6H+( aq)→ I -( aq)+ 3S 4O6 2 − aq)+ 3H 2O( l) D) IO3 −( aq)+ I2( aq)+ 8S2O32 −( aq)+ 6H+( aq)→ 3I-( aq)+ 4S4O62 −( aq)+ 3H2O( l) E) IO3( aq)+ 2I2( aq)+ 6S2O32 −(aq)+ 6H+( aq)→ 5I -( aq)+ 3S4O62−( aq)+ 3H2O( l) A) IO 3 −( aq)+ 3I −( aq)+ 2S 2O3 2 − aq)+ 6H+( aq)→ 2I 2( aq)+ S 4O6 2 −( aq)+ 3H 2O( l) B) IO 3( aq)+ 4S 2O3 2 −( aq)+ 6H+( aq)→ I −( aq)+ 2S 4O6 2 −( aq)+ 3H 2O( l) C) IO 3− aq)+ 6S 2O3 2 − aq)+ 6H+( aq)→ I -( aq)+ 3S 4O6 2 − aq)+ 3H 2O( l) D) IO3 −( aq)+ I2( aq)+ 8S2O32 −( aq)+ 6H+( aq)→ 3I-( aq)+ 4S4O62 −( aq)+ 3H2O( l) E) IO3( aq)+ 2I2( aq)+ 6S2O32 −(aq)+ 6H+( aq)→ 5I -( aq)+ 3S4O62−( aq)+ 3H2O( l) C

An important reaction sequence in the industrial production of nitric acid is the following: N2(g) + 3H2(g) → 2NH3(g) 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(l) Starting from 20.0 mol of nitrogen gas in the first reaction, how many moles of oxygen gas are required in the second one?

A) 12.5 mol O 2 B) 20.0 mol O 2 C) 25.0 mol O 2 D) 50.0 mol O 2 E) 100. mol O 2 A) 12.5 mol O 2 B) 20.0 mol O 2 C) 25.0 mol O 2 D) 50.0 mol O 2 E) 100. mol O 2 D

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

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

Calculate the molar mass of rubidium carbonate, Rb2CO3.

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

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

A) B 2O 3( s)+ 6HF( l)→ 2BF 3( g)+ 3H 2O( l) B) B 2O 3( s)+ H 6F 6( l)→ B 2F 6( g)+ H 6O 3( l) C) B 2O 3( s)+ 2HF( l)→ 2BF 3( g)+ H 2O( l) D) B 2O 3( s)+ 3HF( l)→ 2BF 3( g)+ 3H 2O( l) E) B 2O 3( s)+ 6HF( l)→ 2BF 3( g)+ 6H 2O( l) A) B 2O 3( s)+ 6HF( l)→ 2BF 3( g)+ 3H 2O( l) B) B 2O 3( s)+ H 6F 6( l)→ B 2F 6( g)+ H 6O 3( l) C) B 2O 3( s)+ 2HF( l)→ 2BF 3( g)+ H 2O( l) D) B 2O 3( s)+ 3HF( l)→ 2BF 3( g)+ 3H 2O( l) E) B 2O 3( s)+ 6HF( l)→ 2BF 3( g)+ 6H 2O( l)

Calculate the mass in grams of 8.35 × 1022 molecules of CBr4.

A) 0.0217 g B) 0.139 g C) 7.21 g D) 12.7 g E) 46.0 g A) 0.0217 g B) 0.139 g C) 7.21 g D) 12.7 g E) 46.0 g

The number of hydrogen atoms in 0.050 mol of C3H8O3 is

A) 3.0 × 10 22 H atoms. B) 1.2 × 10 23 H atoms. C) 2.4 × 10 23 H atoms. D) 4.8 × 10 23 H atoms. E) None of these choices are correct. A) 3.0 × 10 22 H atoms. B) 1.2 × 10 23 H atoms. C) 2.4 × 10 23 H atoms. D) 4.8 × 10 23 H atoms. E) None of these choices are correct.

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

A) Ca 3(PO 4)2( s)+ 3SiO 2( s)+ 8C( s)→ 3CaSiO 3( s)+ 8CO( g)+ P4( s) B) Ca 3(PO 4)2( s)+ 3SiO 2( s)+ 14C(s)→ 3CaSiO 3( s)+ 14CO( g)+ P 4( s) C) Ca 3(PO 4)2( s)+ 3SiO 2( s)+ 8C( s)→ 3CaSiO 3( s)+ 8CO( g)+ 2P 4( s) D) 2Ca 3(PO 4)2( s)+ 6SiO 2( s)+ 10C( s)→ 6CaSiO 3( s)+ 10CO( g)+ P 4( s) E) 2Ca 3(PO 4)2( s)+ 6SiO 2( s)+ 10C( s)→ 6CaSiO 3( s)+ 10CO( g)+ 4P 4( s) A) Ca 3(PO 4)2( s)+ 3SiO 2( s)+ 8C( s)→ 3CaSiO 3( s)+ 8CO( g)+ P4( s) B) Ca 3(PO 4)2( s)+ 3SiO 2( s)+ 14C(s)→ 3CaSiO 3( s)+ 14CO( g)+ P 4( s) C) Ca 3(PO 4)2( s)+ 3SiO 2( s)+ 8C( s)→ 3CaSiO 3( s)+ 8CO( g)+ 2P 4( s) D) 2Ca 3(PO 4)2( s)+ 6SiO 2( s)+ 10C( s)→ 6CaSiO 3( s)+ 10CO( g)+ P 4( s) E) 2Ca 3(PO 4)2( s)+ 6SiO 2( s)+ 10C( s)→ 6CaSiO 3( s)+ 10CO( g)+ 4P 4( s)

Tetraphosphorus hexaoxide ( ℳ = 219.9 g/mol) is formed by the reaction of phosphorus with oxygen gas. P4(s) + 3O2(g) → P4O6(s) 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?

A) 57.5% B) 48.8% C) 38.0% D) 32.4% E) 16.3% A) 57.5% B) 48.8% C) 38.0% D) 32.4% E) 16.3%

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 (ℳ = 24.31 g/mol) and 175 g of iron(III) chloride (ℳ = 162.2 g/mol) is allowed to react. What mass of magnesium chloride (ℳ = 95.21 g/mol) is formed?

A) 68.5 g MgCl 2 B) 77.0 g MgCl 2 C) 71.4 g MgCl 2 D) 107 g MgCl 2 E) 154 g MgCl 2 A) 68.5 g MgCl 2 B) 77.0 g MgCl 2 C) 71.4 g MgCl 2 D) 107 g MgCl 2 E) 154 g MgCl 2

Exam 3: Stoichiometry of Formulas and Equations

The iodine "clock reaction" involves the following sequence of reactions occurring in a reaction mixture in a single beaker. 1.IO₃(aq) + 5I⁻(aq) + 6H⁺(aq) → 3I₂(aq) + 3H₂O(l) 2.I₂(aq) + 2S₂O₃²⁻(aq) → 2I⁻(aq) + S₄O₆²⁻aq) The molecular iodine (I₂) formed in reaction 1 is immediately used up in reaction 2, so that no iodine accumulates. What is the overall reaction occurring in this experiment?

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(Multiple Choice)

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Question 1

Correct Answer:

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Aluminum oxide, Al₂O₃, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al₂O₃.

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Question 2

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An important reaction sequence in the industrial production of nitric acid is the following: N₂(g) + 3H₂(g) → 2NH₃(g) 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(l) Starting from 20.0 mol of nitrogen gas in the first reaction, how many moles of oxygen gas are required in the second one?

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(Multiple Choice)

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Question 3

Correct Answer:

Verified

Potassium dichromate, K₂Cr₂O₇, is used in tanning leather, decorating porcelain, and water proofing fabrics. Calculate the number of chromium atoms in 78.82 g of K₂Cr₂O₇.

(Multiple Choice)

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Question 4

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

(Multiple Choice)

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Question 5

Ammonia, an important source of fixed nitrogen that can be metabolized by plants, is produced using the Haber process in which nitrogen and hydrogen combine. N₂(g) + 3H₂(g) → 2NH₃(g) How many grams of nitrogen are needed to produce 325 grams of ammonia?

(Multiple Choice)

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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.

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Question 7

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na₂SO₄.

(Multiple Choice)

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Question 8

A normal breath takes in about 1.0 L of air. Assuming that air has an average molar mass of 28.8 g, and that its density is 0.97 g/L, how many molecules of air do you take in with each breath?

(Multiple Choice)

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Question 9

Calculate the molar mass of rubidium carbonate, Rb₂CO₃.

(Multiple Choice)

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Question 10

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

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Question 11

Hydroxylamine hydrochloride is a powerful reducing agent which is used as a polymerization catalyst. It contains 5.80 mass % H, 20.16 mass % N, 23.02 mass % O, and 51.02 mass % Cl. What is its empirical formula?

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Question 12

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)

(Multiple Choice)

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Question 13

Calculate the mass in grams of 8.35 × 10²² molecules of CBr₄.

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Question 14

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 CO₂and 0.226 g H₂O. What is its empirical formula?

(Multiple Choice)

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Question 15

The number of hydrogen atoms in 0.050 mol of C₃H₈O₃ is

(Multiple Choice)

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Question 16

The iodine "clock reaction" involves the following sequence of reactions occurring in a reaction mixture in a single beaker. IO₃(aq) + 5I^-(aq) + 6H⁺(aq) → 3I₂(aq) + 3H₂O(l) I₂(aq) + 2S₂O₃²^-(aq) → 2I^-(aq) + S₄O₆²^-(aq) The molecular iodine (I₂) formed in reaction 1 is immediately used up in reaction 2, so that no iodine accumulates. In one experiment, a student made up a reaction mixture which initially contained 0.0020 mol of iodate ions (IO₃⁻). If the iodate ions reacted completely, how many moles of thiosulfate ions (S₂O₃²⁻) were needed in reaction 2, in order to react completely with the iodine (I₂) produced in reaction 1?

(Multiple Choice)

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Question 17

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

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Question 18

Tetraphosphorus hexaoxide ( ℳ = 219.9 g/mol) is formed by the reaction of phosphorus with oxygen gas. P₄(s) + 3O₂(g) → P₄O₆(s) 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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Question 19

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 (ℳ = 24.31 g/mol) and 175 g of iron(III) chloride (ℳ = 162.2 g/mol) is allowed to react. What mass of magnesium chloride (ℳ = 95.21 g/mol) is formed?

(Multiple Choice)

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Question 20

Showing 1 - 20 of 72

Exam 3: Stoichiometry of Formulas and Equations

Aluminum oxide, Al2O3, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al2O3.

An important reaction sequence in the industrial production of nitric acid is the following: N2(g) + 3H2(g) → 2NH3(g) 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(l) Starting from 20.0 mol of nitrogen gas in the first reaction, how many moles of oxygen gas are required in the second one?

Potassium dichromate, K2Cr2O7, is used in tanning leather, decorating porcelain, and water proofing fabrics. Calculate the number of chromium atoms in 78.82 g of K2Cr2O7.

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

Ammonia, an important source of fixed nitrogen that can be metabolized by plants, is produced using the Haber process in which nitrogen and hydrogen combine. N2(g) + 3H2(g) → 2NH3(g) How many grams of nitrogen are needed to produce 325 grams of ammonia?

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

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na2SO4.

A normal breath takes in about 1.0 L of air. Assuming that air has an average molar mass of 28.8 g, and that its density is 0.97 g/L, how many molecules of air do you take in with each breath?

Calculate the molar mass of rubidium carbonate, Rb2CO3.

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

Hydroxylamine hydrochloride is a powerful reducing agent which is used as a polymerization catalyst. It contains 5.80 mass % H, 20.16 mass % N, 23.02 mass % O, and 51.02 mass % Cl. What is its empirical formula?

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)

Calculate the mass in grams of 8.35 × 1022 molecules of CBr4.

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?

The number of hydrogen atoms in 0.050 mol of C3H8O3 is

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

Tetraphosphorus hexaoxide ( ℳ = 219.9 g/mol) is formed by the reaction of phosphorus with oxygen gas. P4(s) + 3O2(g) → P4O6(s) 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?

Keys to the Study of Chemistry: Definitions, Units, and Problem Solving

The Components of Matter

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and Reaction Direction

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

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Aluminum oxide, Al₂O₃, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al₂O₃.

An important reaction sequence in the industrial production of nitric acid is the following: N₂(g) + 3H₂(g) → 2NH₃(g) 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(l) Starting from 20.0 mol of nitrogen gas in the first reaction, how many moles of oxygen gas are required in the second one?

Potassium dichromate, K₂Cr₂O₇, is used in tanning leather, decorating porcelain, and water proofing fabrics. Calculate the number of chromium atoms in 78.82 g of K₂Cr₂O₇.

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

Ammonia, an important source of fixed nitrogen that can be metabolized by plants, is produced using the Haber process in which nitrogen and hydrogen combine. N₂(g) + 3H₂(g) → 2NH₃(g) How many grams of nitrogen are needed to produce 325 grams of ammonia?

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

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na₂SO₄.

Calculate the molar mass of rubidium carbonate, Rb₂CO₃.

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

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)

Calculate the mass in grams of 8.35 × 10²² molecules of CBr₄.

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 CO₂and 0.226 g H₂O. What is its empirical formula?

The number of hydrogen atoms in 0.050 mol of C₃H₈O₃ is

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

Tetraphosphorus hexaoxide ( ℳ = 219.9 g/mol) is formed by the reaction of phosphorus with oxygen gas. P₄(s) + 3O₂(g) → P₄O₆(s) 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?