Galvanic and Electrolytic Cells 9.7

Which of the following is true about the voltaic cell?

• Sn is the cathode; Ag is the anode; electrons flow from the right to the left

• Sn is the anode; Ag is the cathode; electrons flow from the right to the left

• Sn is the anode; Ag is the cathode; electrons flow from the left to the right

• Sn is the cathode; Ag is the anode; electrons flow from the left to the right

Which rxn occurs at the cathode of an electrode cell containing a mixture of molten KCL and ZnCl2?

• Zn2+(l) + 2e- --> Zn(s)

• 2Cl-(l) --> Cl2(g) + 2e-

• K(s) --> K+(l) + e-

• K+(1) + e- --> K(s)

What rxn (oxidation or reduction) occurs at the anode of a voltaic cell? What is the sign of the anode? Do electrons flow toward or away from the anode?

• Reduction

  (+)

  Toward the anode

• Reduction

  (-)

  Away from the anode

• Oxidation

  (-)

  Away from the anode

• Oxidation

  (+)

  Toward the anode

Which combination will have the most thermodynamically favorable reaction with the reduction rxn: Cu2+(aq) + 2 e- → Cu(s) (E° = 0.34 V)?

(Cu2+ must be reduced)

• Au3+(aq) + 3e- --> Au(s)

• Ni2+(aq) + 2e- --> Ni(s)

• Mn2+(aq) + 2e- --> Mn(s)

After a reaction takes place:

• The anode will dissolve in the solution, form ions, and decrease in mass. The cathode will increase in size as a solid metal forms from the ions.

• The cathode will dissolve in the solution, form ions, and decrease in mass. The anode will increase in size as a solid metal forms from the ions.