Question 1

How many molecules of N2O4 are in 76.3 g N2O4? The molar mass of N2O4 is 92.02 g mol-1.

Accepted Answer

A)  5.54 × 1025 N2O4 molecules 
B)  7.26 × 1023 N2O4 molecules 
C)  1.38 × 1024 N2O4 molecules 
D)  4.59 × 1025 N2O4 molecules 
E)  4.99 × 1023 N2O4 molecules 
A)  5.54 × 1025 N2O4 molecules 
B)  7.26 × 1023 N2O4 molecules 
C)  1.38 × 1024 N2O4 molecules 
D)  4.59 × 1025 N2O4 molecules 
E)  4.99 × 1023 N2O4 molecules

Question 2

Which of the following is a molecular compound?

Accepted Answer

A)  NaCN 
B)  LiOH 
C)  SrI2 
D)  ZnS 
E)  P4O10 
A)  NaCN 
B)  LiOH 
C)  SrI2 
D)  ZnS 
E)  P4O10

Question 3

Determine the molecular formula for a compound that is 70.79% carbon, 8.91% hydrogen, 4.59% nitrogen, and 15.72% oxygen.

Accepted Answer

A)  C18H27NO3 
B)  C18H27NO2 
C)  C17H27NO3 
D)  C17H26NO3 
A)  C18H27NO3 
B)  C18H27NO2 
C)  C17H27NO3 
D)  C17H26NO3

Question 4

How many molecules are in 1.500 g of riboflavin, C17H20N4O6?

Accepted Answer

A)  1.066 × 1021 
B)  4.167 × 10-22 
C)  3.400 × 1026 
D)  1.067 × 1024 
E)  2.400 × 1021 
A)  1.066 × 1021 
B)  4.167 × 10-22 
C)  3.400 × 1026 
D)  1.067 × 1024 
E)  2.400 × 1021

Question 5

Describe the difference between an atomic element and a molecular element.

Accepted Answer

Atomic elements exist in natur

Question 6

What is the chemical formula for calcium hydroxide?

Accepted Answer

A)  CaH2 
B)  CaOH 
C)  CaOH2 
D)  Ca(OH)2 
A)  CaH2 
B)  CaOH 
C)  CaOH2 
D)  Ca(OH)2

Question 7

Which of the following is a formula for the compound iridium(III) bromide tetrahydrate?

Accepted Answer

A)  IrBr∙   H2O 
B)  IrBr∙4H2O 
C)  IrBr3∙4H2O 
D)  IBr3∙4H2O 
E)  IBr3∙2H2O 
A)  IrBr∙   H2O 
B)  IrBr∙4H2O 
C)  IrBr3∙4H2O 
D)  IBr3∙4H2O 
E)  IBr3∙2H2O

Question 8

How many molecules are in 114.86 g of vitamin C, C6H8O6?

Accepted Answer

A)  1.218 × 1028 
B)  3.927 × 1023 
C)  2.546 × 10-24 
D)  2.977 × 1019 
E)  2.977 × 1022 
A)  1.218 × 1028 
B)  3.927 × 1023 
C)  2.546 × 10-24 
D)  2.977 × 1019 
E)  2.977 × 1022

Question 9

How many anions are there in 2.50 g of MgBr2?

Accepted Answer

A)  8.18 × 1021 anions 
B)  1.64 × 1022 anions 
C)  4.43 × 1025 anions 
D)  8.87 × 1025 anions 
A)  8.18 × 1021 anions 
B)  1.64 × 1022 anions 
C)  4.43 × 1025 anions 
D)  8.87 × 1025 anions

Question 10

How many atoms of carbon are contained in 47.6 g of Al2(CO3)3? The molar mass of Al2(CO3)3 is 233.99 g mol-1.

Accepted Answer

A)  1.23 × 1023 C atoms 
B)  2.96 × 1024 C atoms 
C)  2.87 × 1025 C atoms 
D)  1.10 × 1024 C atoms 
E)  3.68 × 1023 C atoms 
A)  1.23 × 1023 C atoms 
B)  2.96 × 1024 C atoms 
C)  2.87 × 1025 C atoms 
D)  1.10 × 1024 C atoms 
E)  3.68 × 1023 C atoms

Question 11

Which of the following is a molecular compound?

Accepted Answer

A)  CuCl2 
B)  N2O4 
C)  NaNO3 
D)  SrSO3 
E)  RbBr 
A)  CuCl2 
B)  N2O4 
C)  NaNO3 
D)  SrSO3 
E)  RbBr

Question 12

Identify the name for the compound Fe(C2H3O2)2.

Accepted Answer

A)  iron(II) hydrogen carbonate 
B)  iron(III) carbonate 
C)  iron acetate 
D)  iron(II) acetate 
E)  iron(II) dihydrogen phosphate 
A)  iron(II) hydrogen carbonate 
B)  iron(III) carbonate 
C)  iron acetate 
D)  iron(II) acetate 
E)  iron(II) dihydrogen phosphate

Question 13

An aqueous solution of H2S is named ________.

Accepted Answer

A)  hydrosulfuric acid 
B)  hydrosulfurous acid 
C)  sulfuric acid 
D)  sulfurous acid 
A)  hydrosulfuric acid 
B)  hydrosulfurous acid 
C)  sulfuric acid 
D)  sulfurous acid

Question 14

Combustion analysis of 63.8 mg of a C, H, and O-containing compound produced 145.0 mg of CO2 and 59.38 mg of H2O. What is the empirical formula for the compound?

Accepted Answer

A)  C5H2O 
B)  CHO 
C)  C3H6O 
D)  C3H7O 
E)  C6HO3 
A)  C5H2O 
B)  CHO 
C)  C3H6O 
D)  C3H7O 
E)  C6HO3

Question 15

Combustion analysis of an unknown hydrocarbon produced the following results: C 52.14%, H 13.13%, O 34.73%. Determine the empirical formula.

Accepted Answer

A)  C4H8O2 
B)  C4H12O2 
C)  C2H6O 
D)  C4H6O2 
E)  C6H8O4 
A)  C4H8O2 
B)  C4H12O2 
C)  C2H6O 
D)  C4H6O2 
E)  C6H8O4

Question 16

Identify the correct formula for aluminum sulfate.

Accepted Answer

A)  Al2SO4 
B)  Al(SO4)3 
C)  Al3(SO4)2 
D)  Al2(SO4)3 
A)  Al2SO4 
B)  Al(SO4)3 
C)  Al3(SO4)2 
D)  Al2(SO4)3

Question 17

Calculate the mass percent composition of oxygen in Al2(SO4)3.

Accepted Answer

Question 18

Calculate the number of carbon atoms in 76.91 g of benzoic acid, C6H5COOH.

Accepted Answer

A)  6.693 × 1024 
B)  3.793 × 1023 
C)  2.655 × 1024 
D)  3.767 × 1025  
E)  4.488 × 1020 
A)  6.693 × 1024 
B)  3.793 × 1023 
C)  2.655 × 1024 
D)  3.767 × 1025  
E)  4.488 × 1020

Question 19

Determine the molecular formula of a compound that is 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen. The molecular weight is 194.19 g mol-1.

Accepted Answer

A)  C8H12N4O2 
B)  C4H5N2O 
C)  C8H10N4O2 
D)  C8H10N2O 
A)  C8H12N4O2 
B)  C4H5N2O 
C)  C8H10N4O2 
D)  C8H10N2O

Question 20

What is the charge on the Cr ions in Cr2O3?

Accepted Answer

A)  2- 
B)  1+ 
C)  2+ 
D)  3+ 
A)  2- 
B)  1+ 
C)  2+ 
D)  3+

Exam 3: Molecules, Compounds, and Nomenclature

How many molecules of N2O4 are in 76.3 g N2O4? The molar mass of N2O4 is 92.02 g mol-1.

Which of the following is a molecular compound?

Determine the molecular formula for a compound that is 70.79% carbon, 8.91% hydrogen, 4.59% nitrogen, and 15.72% oxygen.

How many molecules are in 1.500 g of riboflavin, C17H20N4O6?

Describe the difference between an atomic element and a molecular element.

What is the chemical formula for calcium hydroxide?

Which of the following is a formula for the compound iridium(III) bromide tetrahydrate?

How many molecules are in 114.86 g of vitamin C, C6H8O6?

How many anions are there in 2.50 g of MgBr2?

How many atoms of carbon are contained in 47.6 g of Al2(CO3)3? The molar mass of Al2(CO3)3 is 233.99 g mol-1.

Which of the following is a molecular compound?

Identify the name for the compound Fe(C2H3O2)2.

An aqueous solution of H2S is named ________.

Combustion analysis of 63.8 mg of a C, H, and O-containing compound produced 145.0 mg of CO2 and 59.38 mg of H2O. What is the empirical formula for the compound?

Combustion analysis of an unknown hydrocarbon produced the following results: C 52.14%, H 13.13%, O 34.73%. Determine the empirical formula.

Identify the correct formula for aluminum sulfate.

Calculate the mass percent composition of oxygen in Al2(SO4)3.

Calculate the number of carbon atoms in 76.91 g of benzoic acid, C6H5COOH.

Determine the molecular formula of a compound that is 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen. The molecular weight is 194.19 g mol-1.

What is the charge on the Cr ions in Cr2O3?

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Chemical Reactions and Stoichiometry

Gases

Thermochemistry

The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding Ii: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory

Liquids, Solids, and Intermolecular Forces

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Gibbs Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry I: Structures

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Filters

How many molecules of N₂O₄ are in 76.3 g N₂O₄? The molar mass of N₂O₄ is 92.02 g mol^-1.

How many molecules are in 1.500 g of riboflavin, C₁₇H₂₀N₄O₆?

How many molecules are in 114.86 g of vitamin C, C₆H₈O₆?

How many anions are there in 2.50 g of MgBr₂?

How many atoms of carbon are contained in 47.6 g of Al₂(CO₃)₃? The molar mass of Al₂(CO₃)₃is 233.99 g mol^-1.

Identify the name for the compound Fe(C₂H₃O₂)₂.

An aqueous solution of H₂S is named ________.

Combustion analysis of 63.8 mg of a C, H, and O-containing compound produced 145.0 mg of CO₂ and 59.38 mg of H₂O. What is the empirical formula for the compound?

Calculate the mass percent composition of oxygen in Al₂(SO₄)₃.

Calculate the number of carbon atoms in 76.91 g of benzoic acid, C₆H₅COOH.

Determine the molecular formula of a compound that is 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen. The molecular weight is 194.19 g mol^-1.

What is the charge on the Cr ions in Cr₂O₃?