Aqueous potassium iodate (KIO3) and potassium iodide (KI) react in the presence of dilute hydrochloric acid (HCl), as shown below. KIO3(aq) + 5KI(aq) + 6HCl(aq) $\rightarrow$ 3I2(aq) + 6KCl(aq) + 3H2O(l) What mass of iodine (I2) is formed when 15.0 mL of 0.0050 M KIO3 solution reacts with 30.0 mL of 0.010 M KI solution in the presence of excess HCl?

A) 0.023 g I2 B) 0.029 g I2 C) 0.057 g I2 D) 0.046 g I2 E) 0.076 g I2 A) 0.023 g I2 B) 0.029 g I2 C) 0.057 g I2 D) 0.046 g I2 E) 0.076 g I2

In a blast furnace, elemental iron is produced from a mixture of coke (C), iron ore (Fe3O4) and other reactants. An important reaction sequence is: 2C(s) + O2(g) $\rightarrow$2CO(g) Fe3O4(s) + 4CO(g) $\rightarrow$ 3Fe(l) + 4CO2(g) How many moles of iron can be formed in this sequence when 1.00 mol of carbon, as coke, is consumed?

A) 6.00 mol Fe B) 3.00 mol Fe C) 1.33 mol Fe D) 1.25 mol Fe E) 0.750 mol Fe A) 6.00 mol Fe B) 3.00 mol Fe C) 1.33 mol Fe D) 1.25 mol Fe E) 0.750 mol Fe

Copper(II) sulfate pentahydrate, CuSO4·5H2O, is used as a fungicide and algicide. Calculate the mass of oxygen in 1.000 mol of CuSO4·5H2O.

A) 249.7 g B) 144.0 g C) 96.00 g D) 80.00 g E) 64.00 g A) 249.7 g B) 144.0 g C) 96.00 g D) 80.00 g E) 64.00 g

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

A) Ca3(PO4)2(s) + 3SiO2(s) + 8C(s) $\rightarrow$ 3CaSiO3(s) + 8CO(g) + P4(s) B) Ca3(PO4)2(s) + 3SiO2(s) + 14C(s) $\rightarrow$ 3CaSiO3(s) + 14CO(g) + P4(s) C) Ca3(PO4)2(s) + 3SiO2(s) + 8C(s) $\rightarrow$ 3CaSiO3(s) + 8CO(g) + 2P4(s) D) 2Ca3(PO4)2(s) + 6SiO2(s) + 10C(s) $\rightarrow$6CaSiO3(s) + 10CO(g) + P4(s) E) 2Ca3(PO4)2(s) + 6SiO2(s) + 10C(s) $\rightarrow$ 6CaSiO3(s) + 10CO(g) + 4P4(s) A) Ca3(PO4)2(s) + 3SiO2(s) + 8C(s) $\rightarrow$ 3CaSiO3(s) + 8CO(g) + P4(s) B) Ca3(PO4)2(s) + 3SiO2(s) + 14C(s) $\rightarrow$ 3CaSiO3(s) + 14CO(g) + P4(s) C) Ca3(PO4)2(s) + 3SiO2(s) + 8C(s) $\rightarrow$ 3CaSiO3(s) + 8CO(g) + 2P4(s) D) 2Ca3(PO4)2(s) + 6SiO2(s) + 10C(s) $\rightarrow$6CaSiO3(s) + 10CO(g) + P4(s) E) 2Ca3(PO4)2(s) + 6SiO2(s) + 10C(s) $\rightarrow$ 6CaSiO3(s) + 10CO(g) + 4P4(s)

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) $\rightarrow$3I2(aq) + 3H2O(l) 2. I2(aq) + 2S2O32¯(aq) $\rightarrow$ 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) IO3¯(aq) + 3I¯(aq) + 2S2O32¯(aq) + 6H+(aq) $\rightarrow$ 2I2(aq) + S4O62¯(aq) + 3H2O(l) B) IO3¯(aq) + 4S2O32¯(aq) + 6H+(aq) $\rightarrow$ I¯(aq) + 2S4O62¯(aq) + 3H2O(l) C) IO3¯(aq) + 6S2O32¯(aq) + 6H+(aq) $\rightarrow$ I¯(aq) + 3S4O62¯(aq) + 3H2O(l) D) IO3¯(aq) + I2(aq) + 8S2O32¯(aq) + 6H+(aq) $\rightarrow$ 3I¯(aq) + 4S4O62¯(aq) + 3H2O(l) E) IO3¯(aq) + 2I2(aq) + 6S2O32¯(aq) + 6H+(aq) $\rightarrow$ 5I¯(aq) + 3S4O62¯(aq) + 3H2O(l) A) IO3¯(aq) + 3I¯(aq) + 2S2O32¯(aq) + 6H+(aq) $\rightarrow$ 2I2(aq) + S4O62¯(aq) + 3H2O(l) B) IO3¯(aq) + 4S2O32¯(aq) + 6H+(aq) $\rightarrow$ I¯(aq) + 2S4O62¯(aq) + 3H2O(l) C) IO3¯(aq) + 6S2O32¯(aq) + 6H+(aq) $\rightarrow$ I¯(aq) + 3S4O62¯(aq) + 3H2O(l) D) IO3¯(aq) + I2(aq) + 8S2O32¯(aq) + 6H+(aq) $\rightarrow$ 3I¯(aq) + 4S4O62¯(aq) + 3H2O(l) E) IO3¯(aq) + 2I2(aq) + 6S2O32¯(aq) + 6H+(aq) $\rightarrow$ 5I¯(aq) + 3S4O62¯(aq) + 3H2O(l)

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

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

Potassium chlorate (used in fireworks, flares and safety matches) forms oxygen and potassium chloride when heated. KClO3(s) $\rightarrow$ KCl(s) + O2(g) [unbalanced] How many grams of oxygen are formed when 26.4 g of potassium chlorate is heated?

A) 223 g B) 99.1 g C) 10.3 g D) 6.86 g E) 4.60 g A) 223 g B) 99.1 g C) 10.3 g D) 6.86 g E) 4.60 g

Exam 3: Stoichiometry of Formulas and Equations

Sodium chlorate is used as an oxidizer in the manufacture of dyes, explosives and matches. Calculate the mass of solute needed to prepare 1.575 L of 0.00250 M NaClO₃ (м = 106.45 g/mol).

(Multiple Choice)

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Question 61

Calculate the molarity of a 23.55-mL solution which contains 28.24 mg of sodium sulfate (used in dyeing and printing textiles, м = 139.04 g/mol).

(Multiple Choice)

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Question 62

Aqueous potassium iodate (KIO₃) and potassium iodide (KI) react in the presence of dilute hydrochloric acid (HCl), as shown below. KIO₃(aq) + 5KI(aq) + 6HCl(aq) $\rightarrow$ 3I₂(aq) + 6KCl(aq) + 3H₂O(l) What mass of iodine (I₂) is formed when 15.0 mL of 0.0050 M KIO₃ solution reacts with 30.0 mL of 0.010 M KI solution in the presence of excess HCl?

(Multiple Choice)

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Question 63

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

(Multiple Choice)

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Question 64

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.

(Multiple Choice)

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Question 65

In a blast furnace, elemental iron is produced from a mixture of coke (C), iron ore (Fe₃O₄) and other reactants. An important reaction sequence is: 2C(s) + O₂(g) $\rightarrow$ 2CO(g) Fe₃O₄(s) + 4CO(g) $\rightarrow$ 3Fe(l) + 4CO₂(g) How many moles of iron can be formed in this sequence when 1.00 mol of carbon, as coke, is consumed?

(Multiple Choice)

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Question 66

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

(Multiple Choice)

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Question 67

Balance the equation B₂O₃(s) + NaOH(aq) $\rightarrow$ Na₃BO₃(aq) + H₂O(l)

(Essay)

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Question 68

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.

(Multiple Choice)

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Question 69

One mole of methane (CH₄) contains a total of 3 * 10²⁴ atoms.

(True/False)

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Question 70

Copper(II) sulfate pentahydrate, CuSO₄·5H₂O, is used as a fungicide and algicide. Calculate the mass of oxygen in 1.000 mol of CuSO₄·5H₂O.

(Multiple Choice)

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Question 71

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

(Multiple Choice)

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Question 72

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

(Multiple Choice)

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Question 73

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) $\rightarrow$ 3I₂(aq) + 3H₂O(l) 2. I₂(aq) + 2S₂O₃²¯(aq) $\rightarrow$ 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?

(Multiple Choice)

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Question 74

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

(Multiple Choice)

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Question 75

Which of the following samples contains the greatest total number atoms?

(Multiple Choice)

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Question 76

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) $\rightarrow$ 2NH₃(g) How many grams of nitrogen are needed to produce 325 grams of ammonia?

(Multiple Choice)

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Question 77

Potassium chlorate (used in fireworks, flares and safety matches) forms oxygen and potassium chloride when heated. KClO₃(s) $\rightarrow$ KCl(s) + O₂(g) [unbalanced] How many grams of oxygen are formed when 26.4 g of potassium chlorate is heated?

(Multiple Choice)

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Question 78

Hydrochloric acid is widely used as a laboratory reagent in refining ore for the production of tin and tantalum, and as a catalyst in organic reactions. Calculate the number of moles of HCl in 62.85 mL of 0.453 M hydrochloric acid.

(Multiple Choice)

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Question 79

Consider the balanced equation for the combustion of propane, C₃H₈ C₃H₈(g) + 5O₂(g) $\rightarrow$ 3CO₂(g) + 4H₂O(l) If propane reacts with oxygen as above A) what is the limiting reagent in a mixture containing 5.00 g of C₃H₈ and 10.0 g of O₂? B) what mass of CO₂ is formed when 1.00 g of C₃H₈ reacts completely?

(Short Answer)

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Question 80

Showing 61 - 80 of 96

Sodium chlorate is used as an oxidizer in the manufacture of dyes, explosives and matches. Calculate the mass of solute needed to prepare 1.575 L of 0.00250 M NaClO₃ (м = 106.45 g/mol).

Calculate the molarity of a 23.55-mL solution which contains 28.24 mg of sodium sulfate (used in dyeing and printing textiles, м = 139.04 g/mol).

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

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.

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

Balance the equation B₂O₃(s) + NaOH(aq) $\rightarrow$ Na₃BO₃(aq) + H₂O(l)

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.

One mole of methane (CH₄) contains a total of 3 * 10²⁴ atoms.

Copper(II) sulfate pentahydrate, CuSO₄·5H₂O, is used as a fungicide and algicide. Calculate the mass of oxygen in 1.000 mol of CuSO₄·5H₂O.

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

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

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

Which of the following samples contains the greatest total number atoms?

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) $\rightarrow$ 2NH₃(g) How many grams of nitrogen are needed to produce 325 grams of ammonia?

Potassium chlorate (used in fireworks, flares and safety matches) forms oxygen and potassium chloride when heated. KClO₃(s) $\rightarrow$ KCl(s) + O₂(g) [unbalanced] How many grams of oxygen are formed when 26.4 g of potassium chlorate is heated?

Hydrochloric acid is widely used as a laboratory reagent in refining ore for the production of tin and tantalum, and as a catalyst in organic reactions. Calculate the number of moles of HCl in 62.85 mL of 0.453 M hydrochloric acid.

Keys to the Study of Chemistry

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 the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

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Exam 3: Stoichiometry of Formulas and Equations

Sodium chlorate is used as an oxidizer in the manufacture of dyes, explosives and matches. Calculate the mass of solute needed to prepare 1.575 L of 0.00250 M NaClO3 (м = 106.45 g/mol).

Calculate the molarity of a 23.55-mL solution which contains 28.24 mg of sodium sulfate (used in dyeing and printing textiles, м = 139.04 g/mol).

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

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.

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

Balance the equation B2O3(s) + NaOH(aq) →\rightarrow→ Na3BO3(aq) + H2O(l)

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.

One mole of methane (CH4) contains a total of 3 * 1024 atoms.

Copper(II) sulfate pentahydrate, CuSO4·5H2O, is used as a fungicide and algicide. Calculate the mass of oxygen in 1.000 mol of CuSO4·5H2O.

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

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

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

Which of the following samples contains the greatest total number atoms?

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) →\rightarrow→ 2NH3(g) How many grams of nitrogen are needed to produce 325 grams of ammonia?

Potassium chlorate (used in fireworks, flares and safety matches) forms oxygen and potassium chloride when heated. KClO3(s) →\rightarrow→ KCl(s) + O2(g) [unbalanced] How many grams of oxygen are formed when 26.4 g of potassium chlorate is heated?

Hydrochloric acid is widely used as a laboratory reagent in refining ore for the production of tin and tantalum, and as a catalyst in organic reactions. Calculate the number of moles of HCl in 62.85 mL of 0.453 M hydrochloric acid.

Keys to the Study of Chemistry

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 the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Sodium chlorate is used as an oxidizer in the manufacture of dyes, explosives and matches. Calculate the mass of solute needed to prepare 1.575 L of 0.00250 M NaClO₃ (м = 106.45 g/mol).

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.

Balance the equation B₂O₃(s) + NaOH(aq) $\rightarrow$ Na₃BO₃(aq) + H₂O(l)

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.

One mole of methane (CH₄) contains a total of 3 * 10²⁴ atoms.

Copper(II) sulfate pentahydrate, CuSO₄·5H₂O, is used as a fungicide and algicide. Calculate the mass of oxygen in 1.000 mol of CuSO₄·5H₂O.

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

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

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) $\rightarrow$ 2NH₃(g) How many grams of nitrogen are needed to produce 325 grams of ammonia?

Potassium chlorate (used in fireworks, flares and safety matches) forms oxygen and potassium chloride when heated. KClO₃(s) $\rightarrow$ KCl(s) + O₂(g) [unbalanced] How many grams of oxygen are formed when 26.4 g of potassium chlorate is heated?