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) → 2CO(g) Fe3O4(s) + 4CO(g) → 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

Balance the following equation for the combustion of benzene: C6H6(l) + O2(g) → H2O(g) + CO2(g)

A) C6H6(l) + 9O2(g) → 3H2O(g) + 6CO2(g) B) C6H6(l) + 9O2(g) → 6H2O(g) + 6CO2(g) C) 2C6H6(l) + 15O2(g) → 6H2O(g) + 12CO2(g) D) C6H6(l) + 15O2(g) → 3H2O(g) + 6CO2(g) E) 2C6H6(l) + 9O2(g) → 6H2O(g) + 12CO2(g) A) C6H6(l) + 9O2(g) → 3H2O(g) + 6CO2(g) B) C6H6(l) + 9O2(g) → 6H2O(g) + 6CO2(g) C) 2C6H6(l) + 15O2(g) → 6H2O(g) + 12CO2(g) D) C6H6(l) + 15O2(g) → 3H2O(g) + 6CO2(g) E) 2C6H6(l) + 9O2(g) → 6H2O(g) + 12CO2(g)

In the combustion analysis of 0.1127 g of glucose (C6H12O6), what mass, in grams, of CO2 would be produced?

A) 0.0451 g B) 0.0825 g C) 0.1652 g D) 0.4132 g E) 1.466 g A) 0.0451 g B) 0.0825 g C) 0.1652 g D) 0.4132 g E) 1.466 g

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 O2 B) 20.0 mol O2 C) 25.0 mol O2 D) 50.0 mol O2 E) 100. mol O2 A) 12.5 mol O2 B) 20.0 mol O2 C) 25.0 mol O2 D) 50.0 mol O2 E) 100. mol O2

Calculate the molar mass of Ca(BO2)2·6H2O.

A) 273.87 g/mol B) 233.79 g/mol C) 183.79 g/mol D) 174.89 g/mol E) 143.71 g/mol A) 273.87 g/mol B) 233.79 g/mol C) 183.79 g/mol D) 174.89 g/mol E) 143.71 g/mol

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

Potassium chlorate (used in fireworks, flares, and safety matches) forms oxygen and potassium chloride when heated. KClO3(s) → 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

Lead(II) sulfide was once used in glazing earthenware. It will also react with hydrogen peroxide to form lead(II) sulfate and water. How many grams of hydrogen peroxide are needed to react completely with 265 g of lead(II) sulfide?

(Multiple Choice)

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Question 41

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 42

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) → 2CO(g) Fe₃O₄(s) + 4CO(g) → 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 43

Determine the percent composition of potassium dichromate, K₂Cr₂O₇.

(Multiple Choice)

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Question 44

In a correctly balanced equation, the number of reactant molecules must equal the number of product molecules.

(True/False)

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Question 45

Balance the following equation for the combustion of benzene: C₆H₆(l) + O₂(g) → H₂O(g) + CO₂(g)

(Multiple Choice)

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Question 46

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

(Multiple Choice)

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Question 47

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 48

How many grams of oxygen are needed to react completely with 200.0 g of ammonia, NH₃? 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g)

(Multiple Choice)

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Question 49

In the combustion analysis of 0.1127 g of glucose (C₆H₁₂O₆), what mass, in grams, of CO₂ would be produced?

(Multiple Choice)

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Question 50

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?

(Multiple Choice)

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Question 51

Calculate the molar mass of Ca(BO₂)₂·6H₂O.

(Multiple Choice)

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Question 52

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 53

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

(Multiple Choice)

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Question 54

Lead (II) nitrate is a poisonous substance which has been used in the manufacture of special explosives and as a sensitizer in photography. Calculate the mass of lead in 139 g of Pb(NO₃)₂.

(Multiple Choice)

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Question 55

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

(True/False)

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Question 56

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)

(Multiple Choice)

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Question 57

Potassium chlorate (used in fireworks, flares, and safety matches) forms oxygen and potassium chloride when heated. KClO₃(s) → 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 58

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 ( = 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.

(Multiple Choice)

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Question 59

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 60

Showing 41 - 60 of 70

Exam 3: Stoichiometry of Formulas and Equations

Lead(II) sulfide was once used in glazing earthenware. It will also react with hydrogen peroxide to form lead(II) sulfate and water. How many grams of hydrogen peroxide are needed to react completely with 265 g of lead(II) sulfide?

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

Determine the percent composition of potassium dichromate, K2Cr2O7.

In a correctly balanced equation, the number of reactant molecules must equal the number of product molecules.

Balance the following equation for the combustion of benzene: C6H6(l) + O2(g) → H2O(g) + CO2(g)

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

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.

How many grams of oxygen are needed to react completely with 200.0 g of ammonia, NH3? 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)

In the combustion analysis of 0.1127 g of glucose (C6H12O6), what mass, in grams, of CO2 would be produced?

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?

Calculate the molar mass of Ca(BO2)2·6H2O.

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.

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

Lead (II) nitrate is a poisonous substance which has been used in the manufacture of special explosives and as a sensitizer in photography. Calculate the mass of lead in 139 g of Pb(NO3)2.

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

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)

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

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

Keys to Studying 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

Filters

Determine the percent composition of potassium dichromate, K₂Cr₂O₇.

Balance the following equation for the combustion of benzene: C₆H₆(l) + O₂(g) → H₂O(g) + CO₂(g)

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.

How many grams of oxygen are needed to react completely with 200.0 g of ammonia, NH₃? 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g)

In the combustion analysis of 0.1127 g of glucose (C₆H₁₂O₆), what mass, in grams, of CO₂ would be produced?

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?

Calculate the molar mass of Ca(BO₂)₂·6H₂O.

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.

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

Lead (II) nitrate is a poisonous substance which has been used in the manufacture of special explosives and as a sensitizer in photography. Calculate the mass of lead in 139 g of Pb(NO₃)₂.

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

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)

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