Question 1

Write a balanced chemical equation for the oxidation of solid cadmium by concentrated nitric acid,producing nitrogen dioxide gas and Cd2+(aq)ion.

Accepted Answer

A)  HNO3(aq)+ Cd(s)→ Cd2+(aq)+ NO2(g)+ OH-(aq) 
B)  2 HNO3(aq)+ Cd(s)→ Cd2+(aq)+ 2 NO2(g)+ 2 OH-(aq) 
C)  HNO3(aq)+ Cd(s)+ H+(aq)→ Cd2+(aq)+ NO2(g)+ H2O(  ) 
D)  4 HNO3(aq)+ Cd(s)→ Cd2+(aq)+ 2 NO2(g)+ 2 H2O(  )+ 2 NO3-(aq) 
E)  HNO3(aq)+ Cd(s)→ Cd2+(aq)+ NO2(g)

Question 2

If ΔrG° for the following reaction is -22.2 kJ/mol-rxn,calculate  for the following reaction: Cu2+(aq)+ 2 Ag(s)+ 2 Cl-(aq)→ Cu(s)+ 2 AgCl(s)

Accepted Answer

A)  -0.460 V 
B)  -0.115 V 
C)  +0.115 V 
D)  +0.230 V 
E)  +0.559 V

Question 3

How many moles of electrons are produced from a current of 17.0 A in 3.40 hours?

Accepted Answer

A)  5.99 × 10-4 mol 
B)  2.16 mol 
C)  57.8 mol 
D)  3.35 mol 
E)  9.33 × 103 mol

Question 4

Calculate the equilibrium constant for the reaction below at 25 °C. Co(s)+ 2 Cr3+(aq)→ Co2+(aq)+ 2 Cr2+(aq)
The standard reduction potentials are as follows:
Co2+(aq)+ 2 e- → Co(s)
E° = -0.28 V
Cr3+(aq)+ e- → Cr2+(aq)
E° = -0.41 V

Accepted Answer

A)  4.0 × 10-5 
B)  2.5 × 104 
C)  1.0 × 105 
D)  1.2 × 105 
E)  1.3 × 105

Question 5

If an electric current is passed through a solution of molten potassium bromide,KBr,the product at the cathode is _____.

Accepted Answer

The answer of If an electric current is passed through...

Question 6

Consider the following half-reactions. Ag+(aq)+ e- → Ag(s)
E° = +0.80 V
Cu2+(aq)+ 2 e- → Cu(s)
E° = +0.34 V
Pb2+(aq)+ 2 e- → Pb(s)
E° = -0.13 V
Fe2+(aq)+ 2 e- → Fe(s)
E° = -0.44 V
Al3+(aq)+ 3 e- → Al(s)
E° = -1.66 V
Which of the following species will oxidize lead,Pb(s)?

Accepted Answer

A)  Ag+(aq)and Cu2+(aq) 
B)  Ag(s)and Cu(s) 
C)  Fe2+(aq)and Al3+(aq) 
D)  Fe(s)and Al(s) 
E)  Cu2+(aq)and Fe2+(aq)

Question 7

Which of the following statements is true concerning the voltaic cell shown below?

Accepted Answer

A)  The Zn anode mass decreases as the cell discharges. 
B)  The Zn cathode mass increases as the cell discharges. 
C)  The Zn cathode mass decreases as the cell discharges. 
D)  The Zn anode mass increases as the cell discharges. 
E)  The mass of the Zn electrode neither increases nor decreases as the cell discharges.

Question 8

Calculate  for the electrochemical cell Pb(s)|PbCl2(s)| Cl-(aq,1.0 M)|| Fe3+(aq,1.0 M),Fe2+(aq,1.0 M)| Pt(s). The standard reduction potentials are as follows:
Pb2+(aq)+ 2 e- → Pb(s)
E° = -0.126 V
PbCl2(s)+ 2 e- → Pb(s)+ 2 Cl-(aq)
E° = -0.267 V
Fe3+(aq)+ e- → Fe2+(aq)
E° = +0.771 V
Fe2+(aq)+ e- → Fe(s)
E° = -0.44 V

Accepted Answer

A)  -0.504 V 
B)  -0.062 V 
C)  +0.504 V 
D)  +1.038 V 
E)  +1.604 V

Question 9

Write a balanced net ionic equation for the overall reaction represented by the following cell notation. Cu(s)| Cu2+(aq)|| Mn2+(aq)| Mn(s)

Accepted Answer

A)  2 Cu(s)+ Mn2+(aq)→ Mn(s)+ 2 Cu2+(aq) 
B)  Cu(s)+ Cu2+(aq)→ Mn(s)+ Mn2+(aq) 
C)  Cu(s)+ Mn2+(aq)→ Mn(s)+ Cu2+(aq) 
D)  2 Mn(s)+ Cu2+(aq)→ Cu(s)+ 2Mn2+(aq) 
E)  Mn(s)+ Cu2+(aq)→ Cu(s)+ Mn2+(aq)

Question 10

In the given electrochemical cell,which of the following is the cathode half-reaction? Zn(s)| Zn2+(aq)|| Fe3+(aq),Fe2+(aq)| Pt(s)

Accepted Answer

A)  Fe3+(aq)+ e− → Fe2+(aq) 
B)  Fe2+(aq)+ e− → Fe3+(aq) 
C)  Fe2+(aq)+ Pt(s)→ Fe3+(aq)+ e− 
D)  Zn2+(aq)→ Zn(s)+ 2 e− 
E)  Zn(s)→ Zn2+(aq)+ 2 e−

Question 11

Use the following standard reduction potentials to determine which species is the best oxidizing agent. O2(g)+ 4 H+(aq)+ 4 e- → 2 H2O(  )
E° = +1.229 V
Hg22+(aq)+ 2 e- → 2 Hg(  )
E° = +0.789 V
I2(s)+ 2 e- → 2 I-(aq)
E° = +0.535 V

Accepted Answer

A)  I2(s) 
B)  O2(g) 
C)  I-(aq) 
D)  Hg22+(aq) 
E)  H2O(  )

Question 12

A voltaic cell or galvanic cell converts chemical energy to electrical energy.  for the given galvanic cell is -1.80 V. Fe2+(aq)+ 2 Cl-(aq)→ Fe(s)+ Cl2(g)
Calculate the value of ΔrG° for the reaction.

Accepted Answer

A)  -174 kJ 
B)  86.8 kJ 
C)  107 kJ 
D)  174 kJ 
E)  347 kJ

Question 13

How many electrons are transferred in the given reaction? Ni + 2 HCl → Ni Cl2 + H2

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  4

Question 14

Write a balanced net ionic equation for the reaction below in an acidic solution. Cr2O72-(aq)+ Ni(s)→ Cr3+(aq)+ Ni2+(aq)

Accepted Answer

A)  Cr2O72-(aq)+ 3 Ni(s)+ 14 H+(aq)→ 2 Cr3+(aq)+ 3 Ni2+(aq)+ 7 H2O(  ) 
B)  Cr2O72-(aq)+ Ni(s)+ 14 H+(aq)→ 2 Cr3+(aq)+ Ni2+(aq)+ 7 H2O(  ) 
C)  Cr2O72-(aq)+ 3 Ni(s)→ 2 Cr3+(aq)+ 3 Ni2+(aq)+ O2-(aq) 
D)  Cr2O72-(aq)+ Ni(s)+ 14 H+(aq)→ 2 Cr3+(aq)+ Ni2+(aq)+ 7 H2O(  ) 
E)  Cr2O72-(aq)+ 3 Ni(s)+ 7 H+(aq)→ 2 Cr3+(aq)+ 3 Ni2+(aq)+ 7 OH-(aq)

Question 15

Use the following standard reduction potentials to determine which species is the strongest reducing agent. 2 H+(aq)+ 2 e- → H2(g); 0.00 V
K+(aq)+ e- → K(s); -2.93 V
F2(g)+ 2 e- → 2 F-(aq); 2.87 V
Al3+(aq)+ 3 e- → Al(s); -1.66 V
Pb2+(aq)+ 2 e- → Pb(s); -0.13 V

Accepted Answer

A)  Al3+ 
B)  H+ 
C)  Pb2+ 
D)  F- 
E)  K

Question 16

Write a balanced chemical equation for the following reaction in a basic solution. ClO-(aq)+ Cr(OH)3(s)→ Cl-(aq)+ CrO42-(aq)

Accepted Answer

A)  3 ClO-(aq)+ 2 Cr(OH)3(s)+ 4 OH-(aq)→ 3 Cl-(aq)+ 2 CrO42-(aq)+ 5 H2O(  ) 
B)  ClO-(aq)+ Cr(OH)3(s)+ 3 OH-(aq)→ Cl-(aq)+ CrO42-(aq)+ 3 H2O(  ) 
C)  2 ClO-(aq)+ 3 Cr(OH)3(s)+ 3 OH-(aq)→ 2 Cl-(aq)+ 3 CrO42-(aq)+ 6 H2O(  ) 
D)  4 ClO-(aq)+ Cr(OH)3(s)+ 4 OH-(aq)→ Cl-(aq)+ CrO42-(aq)+ 6 H2O(  ) 
E)  ClO-(aq)+ Cr(OH)3(s)→ Cl-(aq)+ CrO42-(aq)+ 3 H+(aq)

Question 17

When the following oxidation-reduction reaction in acidic solution is balanced,what is the lowest whole-number coefficient for Na+(aq)ion? Na(s)+ Ca2+(aq)→ Na+(aq)+ Ca(s)

Accepted Answer

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

Question 18

Which of the following is true for a product-favored reaction at equilibrium?

Accepted Answer

A)  ΔrG° cell > 0 
B)  ΔrG° > 0; E°cell rG° cell rG° > 0; E°cell > 0 
E)  ΔrG° > 0; E°cell = 0

Question 19

Balance the following half-reaction occurring in an acidic solution. NO3-(aq)→ NO(aq)

Accepted Answer

A)  NO3-(aq)+ 4 H+(aq)+ 3 e− → NO(g)+ 2 H2O(l) 
B)  NO3-(aq)+ 2 H2O(l)+ 3 e− → NO(g)+ 4 H+(aq) 
C)  NO3-(aq)+ 4 H+(aq)→ NO(g)+ 2 H2O(l)+ 3 e− 
D)  NO3-(aq)+ 3 e− → NO(g)+ 4 H+(aq)+ 2 H2O(l) 
E)  NO3-(aq)+ 4 H+(aq)→ NO(g)+ 2 H2O(l)

Question 20

Balance the following oxidation-reduction reaction occurring in an acidic solution. MnO4-(aq)+ Cr2+(aq)→ Mn2+(aq)+ Cr3+(aq)

Accepted Answer

A)  MnO4-(aq)+ 8 H+(aq)+ 5 Cr2+(aq)→ Mn2+(aq)+ 4 H2O(l)+ 5 Cr3+(aq) 
B)  MnO4-(aq)+ 8 H+(aq)+ Cr2+(aq)→ Mn2+(aq)+ 4 H2O(l)+ Cr3+(aq) 
C)  MnO4-(aq)+ 4 H2(g)+ 5 Cr2+(aq)→ Mn2+(aq)+ 4 H2O(l)+ 5 Cr3+(aq) 
D)  MnO4-(aq)+ 8 H+(aq)+ 2 Cr2+(aq)→ Mn2+(aq)+ 4 H2O(l)+ 2 Cr3+(aq) 
E)  MnO4-(aq)+ Cr2+(aq)→ Mn2+(aq)+ 2 O2(g)+ Cr3+(aq)

Exam 20: Principles of Chemical Reactivity: Electron Transfer Reactions

Write a balanced chemical equation for the oxidation of solid cadmium by concentrated nitric acid,producing nitrogen dioxide gas and Cd²⁺(aq) ion.

If Δ_rG° for the following reaction is -22.2 kJ/mol-rxn,calculate for the following reaction: Cu²⁺(aq) + 2 Ag(s) + 2 Cl^-(aq) → Cu(s) + 2 AgCl(s)

How many moles of electrons are produced from a current of 17.0 A in 3.40 hours?

Calculate the equilibrium constant for the reaction below at 25 °C. Co(s) + 2 Cr³⁺(aq) → Co²⁺(aq) + 2 Cr²⁺(aq) The standard reduction potentials are as follows: Co²⁺(aq) + 2 e^- → Co(s) E° = -0.28 V Cr³⁺(aq) + e^- → Cr²⁺(aq) E° = -0.41 V

If an electric current is passed through a solution of molten potassium bromide,KBr,the product at the cathode is _____.

Which of the following statements is true concerning the voltaic cell shown below?

Write a balanced net ionic equation for the overall reaction represented by the following cell notation. Cu(s) | Cu²⁺(aq) || Mn²⁺(aq) | Mn(s)

In the given electrochemical cell,which of the following is the cathode half-reaction? Zn(s) | Zn²⁺(aq) || Fe³⁺(aq) ,Fe²⁺(aq) | Pt(s)

Use the following standard reduction potentials to determine which species is the best oxidizing agent. O₂(g) + 4 H⁺(aq) + 4 e^- → 2 H₂O( ) E° = +1.229 V Hg₂²⁺(aq) + 2 e^- → 2 Hg( ) E° = +0.789 V I₂(s) + 2 e^- → 2 I^-(aq) E° = +0.535 V

A voltaic cell or galvanic cell converts chemical energy to electrical energy. for the given galvanic cell is -1.80 V. Fe²⁺(aq) + 2 Cl^-(aq) → Fe(s) + Cl₂(g) Calculate the value of Δ_rG° for the reaction.

How many electrons are transferred in the given reaction? Ni + 2 HCl → Ni Cl₂ + H₂

Write a balanced net ionic equation for the reaction below in an acidic solution. Cr₂O₇^2-(aq) + Ni(s) → Cr³⁺(aq) + Ni²⁺(aq)

Use the following standard reduction potentials to determine which species is the strongest reducing agent. 2 H⁺(aq) + 2 e^- → H₂(g) ; 0.00 V K⁺(aq) + e^- → K(s) ; -2.93 V F₂(g) + 2 e^- → 2 F^-(aq) ; 2.87 V Al³⁺(aq) + 3 e^- → Al(s) ; -1.66 V Pb²⁺(aq) + 2 e^- → Pb(s) ; -0.13 V

Write a balanced chemical equation for the following reaction in a basic solution. ClO^-(aq) + Cr(OH) ₃(s) → Cl^-(aq) + CrO₄^2-(aq)

When the following oxidation-reduction reaction in acidic solution is balanced,what is the lowest whole-number coefficient for Na⁺(aq) ion? Na(s) + Ca²⁺(aq) → Na⁺(aq) + Ca(s)

Which of the following is true for a product-favored reaction at equilibrium?

Balance the following half-reaction occurring in an acidic solution. NO₃^-(aq) → NO(aq)

Balance the following oxidation-reduction reaction occurring in an acidic solution. MnO₄^-(aq) + Cr²⁺(aq) → Mn²⁺(aq) + Cr³⁺(aq)

Exam 20: Principles of Chemical Reactivity: Electron Transfer Reactions

Write a balanced chemical equation for the oxidation of solid cadmium by concentrated nitric acid,producing nitrogen dioxide gas and Cd2+(aq) ion.

If ΔrG° for the following reaction is -22.2 kJ/mol-rxn,calculate for the following reaction: Cu2+(aq) + 2 Ag(s) + 2 Cl-(aq) → Cu(s) + 2 AgCl(s)

How many moles of electrons are produced from a current of 17.0 A in 3.40 hours?

Calculate the equilibrium constant for the reaction below at 25 °C. Co(s) + 2 Cr3+(aq) → Co2+(aq) + 2 Cr2+(aq) The standard reduction potentials are as follows: Co2+(aq) + 2 e- → Co(s) E° = -0.28 V Cr3+(aq) + e- → Cr2+(aq) E° = -0.41 V

If an electric current is passed through a solution of molten potassium bromide,KBr,the product at the cathode is _____.

Consider the following half-reactions. Ag+(aq) + e- → Ag(s) E° = +0.80 V Cu2+(aq) + 2 e- → Cu(s) E° = +0.34 V Pb2+(aq) + 2 e- → Pb(s) E° = -0.13 V Fe2+(aq) + 2 e- → Fe(s) E° = -0.44 V Al3+(aq) + 3 e- → Al(s) E° = -1.66 V Which of the following species will oxidize lead,Pb(s) ?

Which of the following statements is true concerning the voltaic cell shown below?

Write a balanced net ionic equation for the overall reaction represented by the following cell notation. Cu(s) | Cu2+(aq) || Mn2+(aq) | Mn(s)

In the given electrochemical cell,which of the following is the cathode half-reaction? Zn(s) | Zn2+(aq) || Fe3+(aq) ,Fe2+(aq) | Pt(s)

Use the following standard reduction potentials to determine which species is the best oxidizing agent. O2(g) + 4 H+(aq) + 4 e- → 2 H2O( ) E° = +1.229 V Hg22+(aq) + 2 e- → 2 Hg( ) E° = +0.789 V I2(s) + 2 e- → 2 I-(aq) E° = +0.535 V

A voltaic cell or galvanic cell converts chemical energy to electrical energy. for the given galvanic cell is -1.80 V. Fe2+(aq) + 2 Cl-(aq) → Fe(s) + Cl2(g) Calculate the value of ΔrG° for the reaction.

How many electrons are transferred in the given reaction? Ni + 2 HCl → Ni Cl2 + H2

Write a balanced net ionic equation for the reaction below in an acidic solution. Cr2O72-(aq) + Ni(s) → Cr3+(aq) + Ni2+(aq)

Use the following standard reduction potentials to determine which species is the strongest reducing agent. 2 H+(aq) + 2 e- → H2(g) ; 0.00 V K+(aq) + e- → K(s) ; -2.93 V F2(g) + 2 e- → 2 F-(aq) ; 2.87 V Al3+(aq) + 3 e- → Al(s) ; -1.66 V Pb2+(aq) + 2 e- → Pb(s) ; -0.13 V

Write a balanced chemical equation for the following reaction in a basic solution. ClO-(aq) + Cr(OH) 3(s) → Cl-(aq) + CrO42-(aq)

When the following oxidation-reduction reaction in acidic solution is balanced,what is the lowest whole-number coefficient for Na+(aq) ion? Na(s) + Ca2+(aq) → Na+(aq) + Ca(s)

Which of the following is true for a product-favored reaction at equilibrium?

Balance the following half-reaction occurring in an acidic solution. NO3-(aq) → NO(aq)

Balance the following oxidation-reduction reaction occurring in an acidic solution. MnO4-(aq) + Cr2+(aq) → Mn2+(aq) + Cr3+(aq)

Write a balanced chemical equation for the oxidation of solid cadmium by concentrated nitric acid,producing nitrogen dioxide gas and Cd²⁺(aq) ion.

If Δ_rG° for the following reaction is -22.2 kJ/mol-rxn,calculate for the following reaction: Cu²⁺(aq) + 2 Ag(s) + 2 Cl^-(aq) → Cu(s) + 2 AgCl(s)

Calculate the equilibrium constant for the reaction below at 25 °C. Co(s) + 2 Cr³⁺(aq) → Co²⁺(aq) + 2 Cr²⁺(aq) The standard reduction potentials are as follows: Co²⁺(aq) + 2 e^- → Co(s) E° = -0.28 V Cr³⁺(aq) + e^- → Cr²⁺(aq) E° = -0.41 V

Write a balanced net ionic equation for the overall reaction represented by the following cell notation. Cu(s) | Cu²⁺(aq) || Mn²⁺(aq) | Mn(s)

In the given electrochemical cell,which of the following is the cathode half-reaction? Zn(s) | Zn²⁺(aq) || Fe³⁺(aq) ,Fe²⁺(aq) | Pt(s)

Use the following standard reduction potentials to determine which species is the best oxidizing agent. O₂(g) + 4 H⁺(aq) + 4 e^- → 2 H₂O( ) E° = +1.229 V Hg₂²⁺(aq) + 2 e^- → 2 Hg( ) E° = +0.789 V I₂(s) + 2 e^- → 2 I^-(aq) E° = +0.535 V

A voltaic cell or galvanic cell converts chemical energy to electrical energy. for the given galvanic cell is -1.80 V. Fe²⁺(aq) + 2 Cl^-(aq) → Fe(s) + Cl₂(g) Calculate the value of Δ_rG° for the reaction.

How many electrons are transferred in the given reaction? Ni + 2 HCl → Ni Cl₂ + H₂

Write a balanced net ionic equation for the reaction below in an acidic solution. Cr₂O₇^2-(aq) + Ni(s) → Cr³⁺(aq) + Ni²⁺(aq)

Write a balanced chemical equation for the following reaction in a basic solution. ClO^-(aq) + Cr(OH) ₃(s) → Cl^-(aq) + CrO₄^2-(aq)

When the following oxidation-reduction reaction in acidic solution is balanced,what is the lowest whole-number coefficient for Na⁺(aq) ion? Na(s) + Ca²⁺(aq) → Na⁺(aq) + Ca(s)

Balance the following half-reaction occurring in an acidic solution. NO₃^-(aq) → NO(aq)

Balance the following oxidation-reduction reaction occurring in an acidic solution. MnO₄^-(aq) + Cr²⁺(aq) → Mn²⁺(aq) + Cr³⁺(aq)