Question 1

________ is the reducing agent in the reaction below. Na(s)+ 2Cl2(g)→ 2NaCl(s)

Accepted Answer

A) Cl2 
B) NaCl 
C) Na+ 
D) Na 
E) Cl- 
A) Cl2 
B) NaCl 
C) Na+ 
D) Na 
E) Cl-

Question 2

In a voltaic cell,electrons flow from the ________ to the ________.

Accepted Answer

A) salt bride, anode 
B) anode, salt bridge 
C) cathode, anode 
D) salt bridge, cathode 
E) anode, cathode 
A) salt bride, anode 
B) anode, salt bridge 
C) cathode, anode 
D) salt bridge, cathode 
E) anode, cathode

Question 3

In a lead-acid battery,the electrodes are consumed.In this battery,________.

Accepted Answer

A) the anode is Pb 
B) the anode is PbSO4 
C) the anode is PbO2 
D) the cathode is PbSO4 
E) the cathode is Pb 
A) the anode is Pb 
B) the anode is PbSO4 
C) the anode is PbO2 
D) the cathode is PbSO4 
E) the cathode is Pb

Question 4

What is the oxidation number of chromium in K2Cr2O7?

Accepted Answer

A) +3 
B) +12 
C) +6 
D) +7 
E) +14 
A) +3 
B) +12 
C) +6 
D) +7 
E) +14

Question 5

One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell,________.

Accepted Answer

A) an electric current is produced by a chemical reaction 
B) electrons flow toward the anode 
C) a nonspontaneous reaction is forced to occur 
D) O2 gas is produced at the cathode 
E) oxidation occurs at the cathode 
A) an electric current is produced by a chemical reaction 
B) electrons flow toward the anode 
C) a nonspontaneous reaction is forced to occur 
D) O2 gas is produced at the cathode 
E) oxidation occurs at the cathode

Question 6

The standard cell potential (E°cell)of the reaction below is +0.126 V.The value of   for the reaction is ________ kJ/mol. Pb (s)+ 2H+(aq)→ Pb2+ (aq)+ H2 (g)

Accepted Answer

A) -24.3 
B) +24.3 
C) -12.6 
D) +12.6 
E) -50.8 
A) -24.3 
B) +24.3 
C) -12.6 
D) +12.6 
E) -50.8

Question 7

What is the oxidation number of oxygen in K2O2?

Accepted Answer

A) -2 
B) +1 
C) -1 
D) +2 
E) -1/2 
A) -2 
B) +1 
C) -1 
D) +2 
E) -1/2

Question 8

Which of the statements about cathodic protection of a metal pipe against corrosion is correct?

Accepted Answer

A) The metal pipe is protected by attaching an active metal to make the pipe the cathode in an electrochemical cell 
B) The metal pipe is protected by coating the pipe with another metal whose standard reduction potential is less negative than that of the pipe 
C) The metal pipe is protected by attaching a dry cell to reduce any metal ions which might be formed 
D) The metal pipe is protected by attaching an active metal to make the pipe the anode in an electrochemical cell 
E) The metal pipe is protected by coating the pipe with a fluoropolymer to act as a source of fluoride ion (since the latter is so hard to oxidize) 
A) The metal pipe is protected by attaching an active metal to make the pipe the cathode in an electrochemical cell 
B) The metal pipe is protected by coating the pipe with another metal whose standard reduction potential is less negative than that of the pipe 
C) The metal pipe is protected by attaching a dry cell to reduce any metal ions which might be formed 
D) The metal pipe is protected by attaching an active metal to make the pipe the anode in an electrochemical cell 
E) The metal pipe is protected by coating the pipe with a fluoropolymer to act as a source of fluoride ion (since the latter is so hard to oxidize)

Question 9

What is the coefficient of   when the following equation is balanced?
CN- + Fe3+ → CNO- + Fe2+  (basic solution)

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 10

How many seconds are required to produce 1.0 g of silver metal by the electrolysis of a AgN   solution using a current of 60 amps?

Accepted Answer

A) 5.4 ×   
B) 3.2 ×   
C) 15 
D) 3.7 ×   
E) 30 
A) 5.4 ×   
B) 3.2 ×   
C) 15 
D) 3.7 ×   
E) 30

Question 11

What is the cathode in an alkaline battery?

Accepted Answer

A) MnO2 
B) KOH 
C) Zn powder 
D) Mn2O3 
E) Pt 
A) MnO2 
B) KOH 
C) Zn powder 
D) Mn2O3 
E) Pt

Question 12

What is a galvanized iron nail?

Accepted Answer

when an iron nail is

Question 13

What is being reduced at the cathode in the hydrogen fuel cell?

Accepted Answer

A) O2 
B) KOH 
C) Li 
D) H2 
E) Pt 
A) O2 
B) KOH 
C) Li 
D) H2 
E) Pt

Question 14

Which of the following reactions will occur spontaneously as written?

Accepted Answer

A) 3Fe2+ (aq)+ Cr3+ (aq)→ Cr (s)+ 3Fe3+ (aq) 
B) 2Cr3+ (aq)+ 3Sn2+ (aq)→ 3Sn4+ (aq)+ 2Cr (s) 
C) Sn4+ (aq)+ Fe2+ (s)→ Sn2+ (aq)+ Fe (s) 
D) Sn2+ (aq)+ Fe2+ (s)→ Sn4+ (aq)+ Fe3+ (aq) 
E) 2Cr (s)+ 3Fe2+ (s)→ 3Fe (s)+ 2Cr3+ (aq) 
A) 3Fe2+ (aq)+ Cr3+ (aq)→ Cr (s)+ 3Fe3+ (aq) 
B) 2Cr3+ (aq)+ 3Sn2+ (aq)→ 3Sn4+ (aq)+ 2Cr (s) 
C) Sn4+ (aq)+ Fe2+ (s)→ Sn2+ (aq)+ Fe (s) 
D) Sn2+ (aq)+ Fe2+ (s)→ Sn4+ (aq)+ Fe3+ (aq) 
E) 2Cr (s)+ 3Fe2+ (s)→ 3Fe (s)+ 2Cr3+ (aq)

Question 15

The standard cell potential (E°cell)for the voltaic cell based on the reaction below is ________ V. 3Sn4+ (aq)+ 2Cr (s)→ 2Cr3+ (aq)+ 3Sn2+ (aq)

Accepted Answer

A) +1.94 
B) +0.89 
C) +2.53 
D) -0.59 
E) -1.02 
A) +1.94 
B) +0.89 
C) +2.53 
D) -0.59 
E) -1.02

Question 16

The standard emf for the cell using the overall cell reaction below is +0.48 V: Zn (s)+   (aq)→   (aq)+ Ni (s)
The emf generated by the cell when [   ] = 0.100 M and [   ] = 2.25 M is

Accepted Answer

A) 0.56 
B) 0.50 
C) 0.44 
D) 0.40 
E) 0.52 
A) 0.56 
B) 0.50 
C) 0.44 
D) 0.40 
E) 0.52

Question 17

The standard cell potential (E°)of a voltaic cell constructed using the cell reaction below is 0.76 V: Zn (s)+   (aq)→   (aq)+   (g)
With   = 1.0 atm and [   ] = 1.0 M,the cell potential is 0.53 V.At 25 °C,the concentration of   in the cathode compartment is ________ M.

Accepted Answer

A) 1.3 × 10-4 
B) 1.7 × 10-8 
C) 1.1 × 10-2 
D) 7.7 × 103 
E) 1.3 × 10-11 
A) 1.3 × 10-4 
B) 1.7 × 10-8 
C) 1.1 × 10-2 
D) 7.7 × 103 
E) 1.3 × 10-11

Question 18

The standard cell potential (E°cell)of the reaction below is +1.34 V.The value of   for the reaction is ________ kJ/mol. 3 Cu (s)+ 2 MnO4- (aq)+ 8H+ (aq)→ 3 Cu2+ (aq)+ 2 MnO2 (s)+ 4 H2O (l)

Accepted Answer

A) -24.3 
B) +259 
C) -259 
D) +776 
E) -776 
A) -24.3 
B) +259 
C) -259 
D) +776 
E) -776

Question 19

A voltaic cell is constructed with two silver-silver chloride electrodes,where the half-reaction is AgCl (s)+   → Ag (s)+   (aq)E° = +0.222 V
The concentrations of chloride ion in the two compartments are 0.0100 M and 1.55 M,respectively.At 25 °C,the cell emf is ________ V.

Accepted Answer

A) 0.216 
B) 0.130 
C) 0.00143 
D) 34.4 
E) 0.228 
A) 0.216 
B) 0.130 
C) 0.00143 
D) 34.4 
E) 0.228

Question 20

At constant ________ and ________ the Gibbs free energy value is a measure of the spontaneity of a process.

Accepted Answer

temperatur

Exam 20: Electrochemistry

________ is the reducing agent in the reaction below. Na(s)+ 2Cl2(g)→ 2NaCl(s)

In a voltaic cell,electrons flow from the ________ to the ________.

In a lead-acid battery,the electrodes are consumed.In this battery,________.

What is the oxidation number of chromium in K2Cr2O7?

One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell,________.

The standard cell potential (E°cell)of the reaction below is +0.126 V.The value of for the reaction is ________ kJ/mol. Pb (s)+ 2H+(aq)→ Pb2+ (aq)+ H2 (g)

What is the oxidation number of oxygen in K2O2?

Which of the statements about cathodic protection of a metal pipe against corrosion is correct?

What is the coefficient of when the following equation is balanced? CN- + Fe3+ → CNO- + Fe2+ (basic solution)

How many seconds are required to produce 1.0 g of silver metal by the electrolysis of a AgN solution using a current of 60 amps?

What is the cathode in an alkaline battery?

What is a galvanized iron nail?

What is being reduced at the cathode in the hydrogen fuel cell?

Which of the following reactions will occur spontaneously as written?

The standard cell potential (E°cell)for the voltaic cell based on the reaction below is ________ V. 3Sn4+ (aq)+ 2Cr (s)→ 2Cr3+ (aq)+ 3Sn2+ (aq)

The standard emf for the cell using the overall cell reaction below is +0.48 V: Zn (s)+ (aq)→ (aq)+ Ni (s) The emf generated by the cell when [ ] = 0.100 M and [ ] = 2.25 M is

The standard cell potential (E°)of a voltaic cell constructed using the cell reaction below is 0.76 V: Zn (s)+ (aq)→ (aq)+ (g) With = 1.0 atm and [ ] = 1.0 M,the cell potential is 0.53 V.At 25 °C,the concentration of in the cathode compartment is ________ M.

The standard cell potential (E°cell)of the reaction below is +1.34 V.The value of for the reaction is ________ kJ/mol. 3 Cu (s)+ 2 MnO4- (aq)+ 8H+ (aq)→ 3 Cu2+ (aq)+ 2 MnO2 (s)+ 4 H2O (l)

A voltaic cell is constructed with two silver-silver chloride electrodes,where the half-reaction is AgCl (s)+ → Ag (s)+ (aq)E° = +0.222 V The concentrations of chloride ion in the two compartments are 0.0100 M and 1.55 M,respectively.At 25 °C,the cell emf is ________ V.

At constant ________ and ________ the Gibbs free energy value is a measure of the spontaneity of a process.

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Chemical Reactions and Reaction Stoichiometry

Reactions in Aqueous Solution

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

________ is the reducing agent in the reaction below. Na(s)+ 2Cl₂(g)→ 2NaCl(s)

In a voltaic cell,electrons flow from the to the .

What is the oxidation number of chromium in K₂Cr₂O₇?

The standard cell potential (E°_cell)of the reaction below is +0.126 V.The value of for the reaction is ________ kJ/mol. Pb (s)+ 2H⁺(aq)→ Pb²⁺ (aq)+ H₂ (g)

What is the oxidation number of oxygen in K₂O₂?

What is the coefficient of when the following equation is balanced? CN^- + Fe³⁺ → CNO^- + Fe²⁺ (basic solution)

The standard cell potential (E°_cell)for the voltaic cell based on the reaction below is ________ V. 3Sn⁴⁺ (aq)+ 2Cr (s)→ 2Cr³⁺ (aq)+ 3Sn²⁺ (aq)

The standard cell potential (E°_cell)of the reaction below is +1.34 V.The value of for the reaction is ________ kJ/mol. 3 Cu (s)+ 2 MnO₄^- (aq)+ 8H⁺ (aq)→ 3 Cu²⁺ (aq)+ 2 MnO₂ (s)+ 4 H₂O (l)

At constant and the Gibbs free energy value is a measure of the spontaneity of a process.