Question 1

Select the precipitate that forms when the following reactants are mixed. Na2CO3(aq) + BaCl2(aq) →

Accepted Answer

A)  Ba2CO3 
B)  BaCO3 
C)  NaCl 
D)  NaCl2 
E)  BaO 
A)  Ba2CO3 
B)  BaCO3 
C)  NaCl 
D)  NaCl2 
E)  BaO

Question 2

Which of the following is a strong acid?

Accepted Answer

A)  H3PO4 
B)  HNO3 
C)  HF 
D)  CH3COOH 
E)  H2O 
A)  H3PO4 
B)  HNO3 
C)  HF 
D)  CH3COOH 
E)  H2O

Question 3

A base

Accepted Answer

A)  causes phenolphthalein indicator to change from colorless to pink. 
B)  donates a proton in a proton transfer reaction. 
C)  accepts electrons in an electron transfer reaction. 
D)  produces hydrogen ions in solution. 
E)  None of these choices are correct. 
A)  causes phenolphthalein indicator to change from colorless to pink. 
B)  donates a proton in a proton transfer reaction. 
C)  accepts electrons in an electron transfer reaction. 
D)  produces hydrogen ions in solution. 
E)  None of these choices are correct.

Question 4

Which one of the following is not a redox reaction?

Accepted Answer

A)  2H2O2(aq) → 2H2O(l) + O2(g) 
B)  N2(g) + 3H2(g) → 2NH3(g) 
C)  BaCl2(aq) + K2CrO4(aq) → BaCrO4(aq) + 2KCl(aq) 
D)  2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(s) 
E)  2H2O(g) → 2H2(g) + O2(g) 
A)  2H2O2(aq) → 2H2O(l) + O2(g) 
B)  N2(g) + 3H2(g) → 2NH3(g) 
C)  BaCl2(aq) + K2CrO4(aq) → BaCrO4(aq) + 2KCl(aq) 
D)  2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(s) 
E)  2H2O(g) → 2H2(g) + O2(g)

Question 5

In an acid-base (neutralization) reaction the equivalence point is the point where the indicator changes color.

Accepted Answer

A) True 
 B)False

Question 6

Calculate the oxidation number of sulfur in sodium metabisulfite, Na2S2O5.

Accepted Answer

A)  -2 
B)  +2 
C)  +4 
D)  +5 
E)  None of these choices are correct. 
A)  -2 
B)  +2 
C)  +4 
D)  +5 
E)  None of these choices are correct.

Question 7

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) → 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?

Accepted Answer

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

Question 8

A 0.00100 mol sample of Ca(OH)2 requires 25.00 mL of aqueous HCl for neutralization according to the reaction below. What is the concentration of the HCl? Equation: Ca(OH)2(s) + 2HCl(aq) → CaCl2(aq) + H2O(l)

Accepted Answer

A)  0.0200 M 
B)  0.0400 M 
C)  0.0800 M 
D)  4.00 × 10-5 M 
E)  None of these choices are correct. 
A)  0.0200 M 
B)  0.0400 M 
C)  0.0800 M 
D)  4.00 × 10-5 M 
E)  None of these choices are correct.

Question 9

A 0.150 M sodium chloride solution is referred to as a physiological saline solution because it has the same concentration of salts as normal human blood. Calculate the mass of solute needed to prepare 275.0 mL of a physiological saline solution.

Accepted Answer

A)  41.3 g 
B)  31.9 g 
C)  16.1 g 
D)  8.77 g 
E)  2.41 g 
A)  41.3 g 
B)  31.9 g 
C)  16.1 g 
D)  8.77 g 
E)  2.41 g

Question 10

Magnesium carbonate, MgCO3, is insoluble. Identify the spectator ions when aqueous solutions of sodium carbonate and magnesium chloride are combined.

Accepted Answer

A)  Mg2+ and CO32- 
B)  Na+ and Cl- 
C)  Mg2+ and Cl- 
D)  Na+ and CO32- 
E)  None of these choices are correct. 
A)  Mg2+ and CO32- 
B)  Na+ and Cl- 
C)  Mg2+ and Cl- 
D)  Na+ and CO32- 
E)  None of these choices are correct.

Question 11

Calcium chloride is used to melt ice and snow on roads and sidewalks and to remove water from organic liquids. Calculate the molarity of a solution prepared by diluting 165 mL of 0.688 M calcium chloride to 925.0 mL.

Accepted Answer

A)  3.86 M 
B)  0.743 M 
C)  0.222 M 
D)  0.123 M 
E)  0.114 M 
A)  3.86 M 
B)  0.743 M 
C)  0.222 M 
D)  0.123 M 
E)  0.114 M

Question 12

Select the precipitate that forms when aqueous lead(II) nitrate reacts with aqueous sodium sulfate.

Accepted Answer

A)  NaNO3 
B)  Na2NO3 
C)  PbSO4 
D)  Pb2SO4 
E)  PbS 
A)  NaNO3 
B)  Na2NO3 
C)  PbSO4 
D)  Pb2SO4 
E)  PbS

Question 13

Select the classification for the following reaction. Na2O(s) + H2O(l) → 2NaOH(aq)

Accepted Answer

A)  Combination 
B)  Decomposition 
C)  Displacement 
D)  Acid-base 
E)  Precipitation 
A)  Combination 
B)  Decomposition 
C)  Displacement 
D)  Acid-base 
E)  Precipitation

Question 14

The amount of calcium present in milk can be determined by adding oxalate to a sample and measuring the mass of calcium oxalate precipitated. What is the mass percent of calcium if 0.429 g of calcium oxalate forms in a 125-g sample of milk when excess aqueous sodium oxalate is added? Na2C2O4(aq) + Ca2+(aq) → CaC2O4(s) + 2Na+(aq)

Accepted Answer

A)  0.107% 
B)  0.202% 
C)  0.343% 
D)  1.10% 
E)  1.37% 
A)  0.107% 
B)  0.202% 
C)  0.343% 
D)  1.10% 
E)  1.37%

Question 15

Lithium hydroxide is used in alkaline batteries. Calculate the molarity of a solution prepared by dissolving 1.495 moles of LiOH in enough water to give a final volume of 750. mL.

Accepted Answer

A)  1.99 M 
B)  1.50 M 
C)  1.12 M 
D)  0.502 M 
E)  0.00199 M 
A)  1.99 M 
B)  1.50 M 
C)  1.12 M 
D)  0.502 M 
E)  0.00199 M

Question 16

Copper(II) sulfide, CuS, is used in the development of aniline black dye in textile printing. What is the maximum mass of CuS which can be formed when 38.0 mL of 0.500 M CuCl2 are mixed with 42.0 mL of 0.600 M (NH4)2S? Aqueous ammonium chloride is the other product.

Accepted Answer

A)  2.41 g 
B)  1.82 g 
C)  1.21 g 
D)  0.909 g 
E)  0.044 g 
A)  2.41 g 
B)  1.82 g 
C)  1.21 g 
D)  0.909 g 
E)  0.044 g

Question 17

The oxidation numbers of P, S, and Cl in H2PO2-, H2S, and KClO4 are, respectively

Accepted Answer

A)  -1, -1, +3. 
B)  -1, -2, +7. 
C)  +1, -2, +7. 
D)  -1, -2, +3. 
E)  +1, +2, +7. 
A)  -1, -1, +3. 
B)  -1, -2, +7. 
C)  +1, -2, +7. 
D)  -1, -2, +3. 
E)  +1, +2, +7.

Question 18

A combination reaction may also be a displacement reaction.

Accepted Answer

A) True 
 B)False

Question 19

Sodium tripolyphosphate is used in detergents to make them effective in hard water. Calculate the oxidation number of phosphorus in Na5P3O10.

Accepted Answer

A)  +3 
B)  +5 
C)  +10 
D)  +15 
E)  None of these choices are correct. 
A)  +3 
B)  +5 
C)  +10 
D)  +15 
E)  None of these choices are correct.

Question 20

In the following reaction, what ions, if any, are spectator ions? Pb(NO3)2(aq) + 2NaCl(aq) → PbCl2(s) + 2NaNO3(aq)

Accepted Answer

A)  Pb2+(aq), Cl-(aq) 
B)  Na+(aq), NO3-(aq) 
C)  Pb2+(aq), NO3-(aq) 
D)  Na+(aq), Cl-(aq) 
E)  There are no spectator ions. 
A)  Pb2+(aq), Cl-(aq) 
B)  Na+(aq), NO3-(aq) 
C)  Pb2+(aq), NO3-(aq) 
D)  Na+(aq), Cl-(aq) 
E)  There are no spectator ions.

Exam 4: Three Major Classes of Chemical Reactions

Select the precipitate that forms when the following reactants are mixed. Na2CO3(aq) + BaCl2(aq) →

Which of the following is a strong acid?

A base

Which one of the following is not a redox reaction?

In an acid-base (neutralization) reaction the equivalence point is the point where the indicator changes color.

Calculate the oxidation number of sulfur in sodium metabisulfite, Na2S2O5.

A 0.00100 mol sample of Ca(OH)2 requires 25.00 mL of aqueous HCl for neutralization according to the reaction below. What is the concentration of the HCl? Equation: Ca(OH)2(s) + 2HCl(aq) → CaCl2(aq) + H2O(l)

A 0.150 M sodium chloride solution is referred to as a physiological saline solution because it has the same concentration of salts as normal human blood. Calculate the mass of solute needed to prepare 275.0 mL of a physiological saline solution.

Magnesium carbonate, MgCO3, is insoluble. Identify the spectator ions when aqueous solutions of sodium carbonate and magnesium chloride are combined.

Calcium chloride is used to melt ice and snow on roads and sidewalks and to remove water from organic liquids. Calculate the molarity of a solution prepared by diluting 165 mL of 0.688 M calcium chloride to 925.0 mL.

Select the precipitate that forms when aqueous lead(II) nitrate reacts with aqueous sodium sulfate.

Select the classification for the following reaction. Na2O(s) + H2O(l) → 2NaOH(aq)

Lithium hydroxide is used in alkaline batteries. Calculate the molarity of a solution prepared by dissolving 1.495 moles of LiOH in enough water to give a final volume of 750. mL.

Copper(II) sulfide, CuS, is used in the development of aniline black dye in textile printing. What is the maximum mass of CuS which can be formed when 38.0 mL of 0.500 M CuCl2 are mixed with 42.0 mL of 0.600 M (NH4)2S? Aqueous ammonium chloride is the other product.

The oxidation numbers of P, S, and Cl in H2PO2-, H2S, and KClO4 are, respectively

A combination reaction may also be a displacement reaction.

Sodium tripolyphosphate is used in detergents to make them effective in hard water. Calculate the oxidation number of phosphorus in Na5P3O10.

In the following reaction, what ions, if any, are spectator ions? Pb(NO3)2(aq) + 2NaCl(aq) → PbCl2(s) + 2NaNO3(aq)

Keys to Studying Chemistry Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

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

Select the precipitate that forms when the following reactants are mixed. Na₂CO₃(aq) + BaCl₂(aq) →

Calculate the oxidation number of sulfur in sodium metabisulfite, Na₂S₂O₅.

A 0.00100 mol sample of Ca(OH)₂ requires 25.00 mL of aqueous HCl for neutralization according to the reaction below. What is the concentration of the HCl? Equation: Ca(OH)₂(s) + 2HCl(aq) → CaCl₂(aq) + H₂O(l)

Magnesium carbonate, MgCO₃, is insoluble. Identify the spectator ions when aqueous solutions of sodium carbonate and magnesium chloride are combined.

Select the classification for the following reaction. Na₂O(s) + H₂O(l) → 2NaOH(aq)

Copper(II) sulfide, CuS, is used in the development of aniline black dye in textile printing. What is the maximum mass of CuS which can be formed when 38.0 mL of 0.500 M CuCl₂ are mixed with 42.0 mL of 0.600 M (NH₄)₂S? Aqueous ammonium chloride is the other product.

The oxidation numbers of P, S, and Cl in H₂PO₂^-, H₂S, and KClO₄ are, respectively

Sodium tripolyphosphate is used in detergents to make them effective in hard water. Calculate the oxidation number of phosphorus in Na₅P₃O₁₀.

In the following reaction, what ions, if any, are spectator ions? Pb(NO₃)₂(aq) + 2NaCl(aq) → PbCl₂(s) + 2NaNO₃(aq)