Question 1

A voltaic cell is made by placing an iron electrode in a compartment in which the Fe²⁺ concentration is 3.0 × 10^-5 M and by placing a Pt electrode in the other compartment,in which the H⁺ concentration is 3.10 M and = 1.00 atm.The Fe²⁺/Fe half-cell reduction potential is -0.41 V,and the H⁺/H₂ half-cell reduction potential is 0.00 V.What is E for the cell at 25^oC?

Accepted Answer

The answer of A voltaic cell is made by placing...

Question 2

Given: What is the cell potential at 25°C for the following cell? Cr(s)| Cr³⁺(0.010 M)|| Ag⁺(0.00025 M)| Ag(s)

Accepted Answer

The answer of Given:   
  
What is...

Question 3

What is one of the major products in the electrolysis of a saturated aqueous sodium chloride solution? Reduction Half-Reaction E° (V) Na⁺(aq)+ e^- Na(s) -2.71 Mg²⁺(aq)+ 2e^- Mg(s) -2.37 2H₂O(l)+ 2e^- H₂(g)+ 2OH^-(aq) -0.83 O₂(g)+ 4H⁺(aq)+ 4e^- 2H₂O(l)1.23 Cl₂(g)+ 2e^- 2Cl^-(aq) 1.36

Accepted Answer

The reduction half-reaction for Cl2 to form 2Cl- has the highest E° value of 1.36 V, indicating that it is the most favorable reduction reaction. Therefore, one of the major products of the electrolysis of a saturated aqueous sodium chloride solution is Cl2 gas.

Question 4

For the cell Cu(s)|Cu²⁺||Ag⁺|Ag(s),the standard cell potential is 0.46 V.A cell using these reagents was made,and the observed potential was 0.29 V at 25^oC.What is a possible explanation for the observed voltage?

Accepted Answer

The Nernst equation shows that a lower observed potential than the standard potential can occur if the concentration of the reactant (Cu²⁺) is higher than that of the product (Ag⁺), shifting the reaction away from equilibrium.

Question 5

Given: Zn²⁺(aq)+ 2e^- Zn(s); E° = -0.76 V Cu²⁺(aq)+ 2e^- Cu(s); E° = 0.34 V What is the cell potential of the following electrochemical cell at 25°C? Zn(s)| Zn²⁺(1.0 M)|| Cu²⁺(0.0010 M)| Cu(s)

Accepted Answer

The answer of Given: Zn²⁺(aq)+ 2e^- Zn(s); E° = -0.76 V Cu²⁺(aq)+...

Question 6

Which of the following statements about batteries is false?

Accepted Answer

It is safe to recharge a nickel-cadmium battery, but overcharging can lead to reduced performance and shorter lifespan. Therefore, it is important to properly monitor and regulate the charging process.

Question 7

Molten magnesium chloride is electrolyzed using inert electrodes and reactions represented by the following two half-reactions: 2Cl^-(l)→ Cl₂(g)+ 2e^- Mg²⁺(l)+ 2e^- → Mg(s) Concerning this electrolysis,which of the following statements is true?

Accepted Answer

Cl^- ions lose electrons to form Cl_2 gas, acting as reducing agents by donating electrons.

Question 8

In order to determine the identity of a particular lanthanide metal (M),a voltaic cell is constructed at 25°C with the anode consisting of the lanthanide metal as the electrode immersed in a solution of 0.0467 M MCl₃,and the cathode consisting of a copper electrode immersed in a 1.00 M Cu(NO₃)₂ solution.The two half-reactions are as follows: M(s) M³⁺(aq)+ 3e^- Cu²⁺(aq)+ 2e^- Cu(s) The potential measured across the cell is 2.70 V.What is the identity of the metal? Reduction Half-Reaction E° (V) Cu²⁺(aq)+ 2e^- Cu(s)0.34 Ce³⁺(aq)+ 3e^- Ce(s)-2.336 Tm³⁺(aq)+ 3e^- Tm(s)-2.319 Eu³⁺(aq)+ 3e^- Eu(s)-1.991 Gd³⁺(aq)+ 3e^- Gd(s)-2.279 Sm³⁺(aq)+ 3e^- Sm(s)-2.304

Accepted Answer

In order for the cell to produce a positive voltage, the reduction half-reaction at the cathode must have a higher standard reduction potential (E°) than the reduction half-reaction at the anode. Among the given options, Ce has the lowest E° of -2.336 V, indicating that it would be the anode in the cell. The reduction half-reaction for copper has the highest E° of 0.34 V, making it the cathode. Therefore, the metal at the anode must have a higher E° than copper but lower E° than Ce. Among the options, only Tm, Gd, Eu, and Sm have higher E° values than copper, but all of them have E° values lower than Ce. Therefore, the metal at the anode must be Ce.

Question 9

What is the copper(II)-ion concentration at 25°C in the cell Zn(s)| Zn²⁺(1.0 M)|| Cu²⁺(aq)| Cu(s)if the measured cell potential is 1.08 V? The standard cell potential is 1.10 V.

Accepted Answer

Using the Nernst equation: 
E = E° - (RT/nF)ln(Q)
where E° is the standard cell potential, R is the gas constant, T is the temperature in Kelvin, n is the number of electrons transferred, F is Faraday's constant, and Q is the reaction quotient.
First, we need to determine the reaction and the corresponding value of Q:
Zn(s) + Cu2+(aq) -> Zn2+(aq) + Cu(s)
Q = [Zn2+]/[Cu2+]
We know that [Zn2+] = 1.0 M (from the given cell diagram) and we need to find [Cu2+]. 
Substitute the given values into the Nernst equation: 
1.08 V = 1.10 V - (RT/2F)ln([Zn2+]/[Cu2+])
Solving for [Cu2+]:
[Cu2+] = [Zn2+]/exp[(1.10 V - 1.08 V)*2F/RT] 
[Cu2+] = 0.21 M (rounded to two significant figures) 
Therefore, the correct answer is C.

Question 10

In order to determine the identity of a particular transition metal (M),a voltaic cell is constructed at 25°C with the anode consisting of the transition metal as the electrode immersed in a solution of 0.0977 M M(NO₃)₂,and the cathode consisting of a copper electrode immersed in a 0.0724M Cu(NO₃)₂ solution.The two half-reactions are as follows: M(s) M²⁺(aq)+ 2e^- Cu²⁺(aq)+ 2e^- Cu(s) The potential measured across the cell is 1.13 V.What is the identity of the metal M? Reduction Half-Reaction E° (V) Cu²⁺(aq)+ 2e^- Cu(s) +0.34 Ni²⁺(aq)+ 2e^- Ni(s) -0.23 Cd²⁺(aq)+ 2e^- Cd(s) - 0.40 Zn²⁺(aq)+ 2e^- Zn(s)-0.76 Mn²⁺(aq)+ 2e^- Mn(s) -1.18

Accepted Answer

The answer of In order to determine the identity of...

Question 11

What half-reaction occurs at the cathode during the electrolysis of molten potassium bromide?

Accepted Answer

During the electrolysis of molten potassium bromide, the reduction half-reaction occurs at the cathode, where potassium ions (K⁺) gain electrons to form potassium metal (K).

Question 12

Cathodic protection results when

Accepted Answer

Cathodic protection is a method of preventing corrosion of a metal surface by connecting it to a more active metal that corrodes more readily. The more active metal (cathode) will corrode instead of the protected metal (anode), effectively protecting the anode from corrosion. Therefore, the correct answer is E, as attaching iron to a more active metal would provide cathodic protection.

Question 13

A piece of iron half-immersed in a sodium chloride solution will corrode more rapidly than a piece of iron half-immersed in pure water,because

Accepted Answer

The presence of ions in the sodium chloride solution facilitates the electrochemical reactions involved in corrosion by balancing the charge between the anodic and cathodic sites, which does not occur as readily in pure water due to its lack of ions.

Question 14

A cell consists of a magnesium electrode immersed in a solution of magnesium chloride and a silver electrode immersed in a solution of silver nitrate.The two half-cells are connected by means of a salt bridge.It is possible to increase the voltage of the cell by

Accepted Answer

Increasing the concentration of Ag+ ions and decreasing the concentration of Mg2+ ions will increase the cell potential according to the Nernst equation, which relates cell potential to ion concentration.

Question 15

What is the value of the reaction quotient,Q,for the voltaic cell constructed from the following two half-reactions when the Zn²⁺ concentration is 0.0120 M and the Ag⁺ concentration is 1.27 M?

Accepted Answer

The answer of What is the value of the reaction...

Question 16

The following cell is initially at standard-state conditions.Which of the following statements is true after the cell is allowed to discharge (do work)for a period of time? Zn²⁺(aq)+ 2e^- Zn(s); E° = -0.76 V Cu²⁺(aq)+ 2e^- Cu(s); E° = 0.34 V

Accepted Answer

The answer of The following cell is initially at standard-state...

Question 17

Which of the following statements is true concerning the electrochemical cell described below at 25^oC? Ni | Ni²⁺(0.381M)|| Ni²⁺(0.317M)| Ni Ni²⁺ (aq)+ 2e¯ Ni (s); Eº = -0.23 V

Accepted Answer

The answer of Which of the following statements is true...

Question 18

For the cell reaction 2MnO₄^- (aq)+ 5SO₂(g)+ 2H₂O(l) → 2Mn²⁺(aq)+ 5SO^2-₄ (aq)+ 4H⁺(aq) The standard cell potential is 1.34 V.To determine the cell potential at nonstandard conditions,what is the value that should be used for n in the Nernst equation?

Accepted Answer

The value of n, which represents the number of moles of electrons transferred in the balanced redox reaction, is 10. This is because each MnO₄⁻ ion gains 5 electrons to form Mn²⁺, and there are 2 MnO₄⁻ ions, resulting in a total of 10 electrons transferred.

Question 19

What is the reduction potential for the half-reaction Al³⁺(aq)+ 3e^- Al(s)at 25°C if [Al³⁺] = 0.18 M and E° = -1.66 V?

Accepted Answer

The answer of What is the reduction potential for the...

Question 20

A voltaic cell is made by placing an iron electrode in a compartment in which the Fe²⁺ concentration is 2.0 × 10^-5 M and by placing a Pt electrode in the other compartment,in which the H⁺ concentration is 3.4 M and = 1.00 atm.The Fe²⁺/Fe half-cell reduction potential is -0.41 V,and the H⁺/H₂ half-cell reduction potential is 0.00 V.What is E for the cell at equilibrium?

Accepted Answer

The answer of A voltaic cell is made by placing...

Quiz 19: Electrochemistry

Given: What is the cell potential at 25°C for the following cell? Cr(s) | Cr³⁺(0.010 M) || Ag⁺(0.00025 M) | Ag(s)

For the cell Cu(s) |Cu²⁺||Ag⁺|Ag(s) ,the standard cell potential is 0.46 V.A cell using these reagents was made,and the observed potential was 0.29 V at 25^oC.What is a possible explanation for the observed voltage?

Given: Zn²⁺(aq) + 2e^- Zn(s) ; E° = -0.76 V Cu²⁺(aq) + 2e^- Cu(s) ; E° = 0.34 V What is the cell potential of the following electrochemical cell at 25°C? Zn(s) | Zn²⁺(1.0 M) || Cu²⁺(0.0010 M) | Cu(s)

Which of the following statements about batteries is false?

Molten magnesium chloride is electrolyzed using inert electrodes and reactions represented by the following two half-reactions: 2Cl^-(l) → Cl₂(g) + 2e^- Mg²⁺(l) + 2e^- → Mg(s) Concerning this electrolysis,which of the following statements is true?

What is the copper(II) -ion concentration at 25°C in the cell Zn(s) | Zn²⁺(1.0 M) || Cu²⁺(aq) | Cu(s) if the measured cell potential is 1.08 V? The standard cell potential is 1.10 V.

What half-reaction occurs at the cathode during the electrolysis of molten potassium bromide?

Cathodic protection results when

A piece of iron half-immersed in a sodium chloride solution will corrode more rapidly than a piece of iron half-immersed in pure water,because

A cell consists of a magnesium electrode immersed in a solution of magnesium chloride and a silver electrode immersed in a solution of silver nitrate.The two half-cells are connected by means of a salt bridge.It is possible to increase the voltage of the cell by

What is the value of the reaction quotient,Q,for the voltaic cell constructed from the following two half-reactions when the Zn²⁺ concentration is 0.0120 M and the Ag⁺ concentration is 1.27 M?

The following cell is initially at standard-state conditions.Which of the following statements is true after the cell is allowed to discharge (do work) for a period of time? Zn²⁺(aq) + 2e^- Zn(s) ; E° = -0.76 V Cu²⁺(aq) + 2e^- Cu(s) ; E° = 0.34 V

Which of the following statements is true concerning the electrochemical cell described below at 25^oC? Ni | Ni²⁺(0.381M) || Ni²⁺(0.317M) | Ni Ni²⁺ (aq) + 2e¯ Ni (s) ; Eº = -0.23 V

For the cell reaction 2MnO₄^- (aq) + 5SO₂(g) + 2H₂O(l) → 2Mn²⁺(aq) + 5SO^2-₄ (aq) + 4H⁺(aq) The standard cell potential is 1.34 V.To determine the cell potential at nonstandard conditions,what is the value that should be used for n in the Nernst equation?

What is the reduction potential for the half-reaction Al³⁺(aq) + 3e^- Al(s) at 25°C if [Al³⁺] = 0.18 M and E° = -1.66 V?

Quiz 19: Electrochemistry

Given: What is the cell potential at 25°C for the following cell? Cr(s) | Cr3+(0.010 M) || Ag+(0.00025 M) | Ag(s)

What is one of the major products in the electrolysis of a saturated aqueous sodium chloride solution? Reduction Half-Reaction E° (V) Na+(aq) + e- Na(s) -2.71 Mg2+(aq) + 2e- Mg(s) -2.37 2H2O(l) + 2e- H2(g) + 2OH-(aq) -0.83 O2(g) + 4H+(aq) + 4e- 2H2O(l) 1.23 Cl2(g) + 2e- 2Cl-(aq) 1.36

For the cell Cu(s) |Cu2+||Ag+|Ag(s) ,the standard cell potential is 0.46 V.A cell using these reagents was made,and the observed potential was 0.29 V at 25oC.What is a possible explanation for the observed voltage?

Given: Zn2+(aq) + 2e- Zn(s) ; E° = -0.76 V Cu2+(aq) + 2e- Cu(s) ; E° = 0.34 V What is the cell potential of the following electrochemical cell at 25°C? Zn(s) | Zn2+(1.0 M) || Cu2+(0.0010 M) | Cu(s)

Which of the following statements about batteries is false?

Molten magnesium chloride is electrolyzed using inert electrodes and reactions represented by the following two half-reactions: 2Cl-(l) → Cl2(g) + 2e- Mg2+(l) + 2e- → Mg(s) Concerning this electrolysis,which of the following statements is true?

What is the copper(II) -ion concentration at 25°C in the cell Zn(s) | Zn2+(1.0 M) || Cu2+(aq) | Cu(s) if the measured cell potential is 1.08 V? The standard cell potential is 1.10 V.

What half-reaction occurs at the cathode during the electrolysis of molten potassium bromide?

Cathodic protection results when

A piece of iron half-immersed in a sodium chloride solution will corrode more rapidly than a piece of iron half-immersed in pure water,because

A cell consists of a magnesium electrode immersed in a solution of magnesium chloride and a silver electrode immersed in a solution of silver nitrate.The two half-cells are connected by means of a salt bridge.It is possible to increase the voltage of the cell by

What is the value of the reaction quotient,Q,for the voltaic cell constructed from the following two half-reactions when the Zn2+ concentration is 0.0120 M and the Ag+ concentration is 1.27 M?

The following cell is initially at standard-state conditions.Which of the following statements is true after the cell is allowed to discharge (do work) for a period of time? Zn2+(aq) + 2e- Zn(s) ; E° = -0.76 V Cu2+(aq) + 2e- Cu(s) ; E° = 0.34 V

Which of the following statements is true concerning the electrochemical cell described below at 25oC? Ni | Ni2+(0.381M​) || Ni2+(0.317M​) | Ni ​Ni2+ (aq​) + 2e¯ ​Ni (s) ; ​E​º = -0.23 V

For the cell reaction 2MnO4- (​aq​) + 5SO2(g) + 2H2O(l) → 2Mn2+(aq) + 5SO2-4 (aq​) + 4H+(aq) The standard cell potential is 1.34 V.To determine the cell potential at nonstandard conditions,what is the value that should be used for n in the Nernst equation?

What is the reduction potential for the half-reaction Al3+(aq) + 3e- Al(s) at 25°C if [Al3+] = 0.18 M and E° = -1.66 V?

Given: What is the cell potential at 25°C for the following cell? Cr(s) | Cr³⁺(0.010 M) || Ag⁺(0.00025 M) | Ag(s)

For the cell Cu(s) |Cu²⁺||Ag⁺|Ag(s) ,the standard cell potential is 0.46 V.A cell using these reagents was made,and the observed potential was 0.29 V at 25^oC.What is a possible explanation for the observed voltage?

Given: Zn²⁺(aq) + 2e^- Zn(s) ; E° = -0.76 V Cu²⁺(aq) + 2e^- Cu(s) ; E° = 0.34 V What is the cell potential of the following electrochemical cell at 25°C? Zn(s) | Zn²⁺(1.0 M) || Cu²⁺(0.0010 M) | Cu(s)

Molten magnesium chloride is electrolyzed using inert electrodes and reactions represented by the following two half-reactions: 2Cl^-(l) → Cl₂(g) + 2e^- Mg²⁺(l) + 2e^- → Mg(s) Concerning this electrolysis,which of the following statements is true?

What is the copper(II) -ion concentration at 25°C in the cell Zn(s) | Zn²⁺(1.0 M) || Cu²⁺(aq) | Cu(s) if the measured cell potential is 1.08 V? The standard cell potential is 1.10 V.

What is the value of the reaction quotient,Q,for the voltaic cell constructed from the following two half-reactions when the Zn²⁺ concentration is 0.0120 M and the Ag⁺ concentration is 1.27 M?

The following cell is initially at standard-state conditions.Which of the following statements is true after the cell is allowed to discharge (do work) for a period of time? Zn²⁺(aq) + 2e^- Zn(s) ; E° = -0.76 V Cu²⁺(aq) + 2e^- Cu(s) ; E° = 0.34 V

Which of the following statements is true concerning the electrochemical cell described below at 25^oC? Ni | Ni²⁺(0.381M) || Ni²⁺(0.317M) | Ni Ni²⁺ (aq) + 2e¯ Ni (s) ; Eº = -0.23 V

For the cell reaction 2MnO₄^- (aq) + 5SO₂(g) + 2H₂O(l) → 2Mn²⁺(aq) + 5SO^2-₄ (aq) + 4H⁺(aq) The standard cell potential is 1.34 V.To determine the cell potential at nonstandard conditions,what is the value that should be used for n in the Nernst equation?

What is the reduction potential for the half-reaction Al³⁺(aq) + 3e^- Al(s) at 25°C if [Al³⁺] = 0.18 M and E° = -1.66 V?