Analytical Chemistry: Electrochemistry

Complete and balance the following redox equation. What is the coefficient of OH- when the equation is balanced using the set of smallest whole-number coefficients?

MnO4- + I- → MnO2 + IO3- (basic solution)

• 1
• 2
• 4
• 10
• None of these

A balanced redox equation must have which of the following:

• I. The same number of each type of atom on both sides of the equation
• II. The total number electrons lost in the oxidation equal to total number of electrons gained in the reduction
• III. The same total charge of all ionic species on both sides of the reaction
• IV. H2O present as a product or a reactant

What is the total number of moles (n) of electrons exchanged between the oxidizing agent and the reducing agent in the overall redox equation:<br />Cr2O7 2- (aq) + 6Fe 2+ (aq) + 14H + (aq) → 2Cr 3+ (aq) + 6Fe 3+ (aq) + 7H2O(l)

• 1
• 2
• 3
• 6
• 12

Complete and balance the following redox equation. The sum of the smallest whole-number coefficients is<br />Br2 → BrO3- + Br- (basic solution)

• 9
• 12
• 18
• 21
• None of these

Consider an electrochemical cell constructed from the following half cells, linked by a KCl salt bridge.<br />- a Fe electrode in 1.0 M FeCl2 solution<br />- a Sn electrode in 1.0 M Sn(NO3)2 solution<br />When the cell is running spontaneously, which choice includes only true statements and no false ones?<br />

• The tin electrode loses mass and the tin electrode is the cathode.
• The tin electrode gains mass and the tin electrode is the cathode.
• The iron electrode gains mass and the iron electrode is the anode.
• The iron electrode gains mass and the iron electrode is the cathode.
• The iron electrode loses mass and the iron electrode is the cathode.

Determine the cell diagram for the reaction below. Assume platinum electrodes are used when no other solid is present.<br /><br />Cl2(g) + Sn2+(aq) → Sn4+(aq) + 2Cl-(aq)

• Pt(s) | Sn4+(aq), Sn2+(aq) || Cl-(aq) | Cl2(g) | Pt(s)
• Pt(s) | Cl2(g) | Cl-(aq) || Sn2+(aq), Sn4+(aq) | Pt(s)
• Pt(s) | Sn2+(aq), Sn4+(aq) || Cl2(g) | Cl-(aq) | Pt(s)
• Pt(s) | Cl2(g) | Sn2+(aq) || Sn4+(aq), Cl-(aq) | Pt(s)
• Pt(s) | Cl-(g) | Cl2(aq) || Sn4+(aq), Sn2+(aq) | Pt(s)

Consider an electrochemical cell constructed from the following half cells, linked by a KCl salt bridge.<br />- a Fe electrode in 1.0 M FeCl2 solution<br />- a Ni electrode in 1.0 M Ni(NO3)2 solution<br />When the cell is running spontaneously, which choice includes only true statements and no false ones?

• The nickel electrode gains mass and the nickel electrode is the cathode.
• The iron electrode gains mass and the iron electrode is the anode.
• The nickel electrode loses mass and the nickel electrode is the cathode.
• The iron electrode loses mass and the iron electrode is the cathode.

Consider a Galvanic cell constructed from the following half cells, linked by an external circuit and by a KCl salt bridge.<br />- an Al(s) electrode in 1.0 M Al(NO3)3 solution<br />- a Pb(s) electrode in 1.0 M Pb(NO3)2 solution<br />The balanced overall (net) cell reaction is:

• 3Pb(s) + 2Al3+ (aq) → 3Pb2+ (aq) + 2Al(s)
• Pb2+(aq) + Al(s) → Pb(s) + Al3+(aq)
• Pb(s) + Al3+ (aq) → Pb2+ (aq) + Al(s)
• 3Pb2+(aq) + 2Al(s) → 3Pb(s) + 2Al3+(aq)

Determine the cell diagram for the reaction below. Assume a platinum electrode is used when no other solid is present.<br /><br />2Fe2+ (aq) + Pb2+ (aq) → 2Fe3+ (aq) + Pb(s)

• Pt(s) | Fe2+(aq), Fe3+(aq) || Pb2+(aq) | Pb(s)
• Pt(s) | Fe2+(aq), Pb2+(aq) || Fe3+(aq) | Pb(s)
• Pt(s) | Pb2+(aq) | Pb(s) || Fe2+(aq), Fe3+(aq) | Pt(s)
• Pb(s) | Pb2+(aq) || Fe2+(aq), Fe3+(aq) | Pt(s)
• Pt(s) | Fe3+(aq), Fe2+(aq) || Pb(s) | Pb2+(aq) | Pt(s)

Consider an electrochemical cell based on the following cell diagram:<br /><br />Pt | Pu3+(aq), Pu4+(aq) || Cl2(g), Cl-(aq) | Pt<br /><br />Given that the standard cell emf is 0.35 V and that the standard reduction potential of chlorine is 1.36 V, what is the standard reduction potential E° (Pu4+/Pu3+)?

• 2.37 V
• –1.01 V
• 1.01 V
• 1.71 V
• –1.71 V