Answer the following questions by selecting the appropriate half-reaction. Assume that in each case the experiment is performed in an electrolysis cell having electrodes made of non-reacting material.

Which half-reaction will take place at the cathode during the electrolysis of molten MgCl2?
Mg2+ + 2e- --> Mg
2Cl- --> Cl2 + 2e-
Cl2 + 2e- --> 2Cl-
Mg --> Mg2+ + 2e-

Which half-reaction will take place at the cathode during the electrolysis of 1.0 M H2O2 solution containing 1.0 M H2SO4?
H2O2 --> O2 + 2H+ + 2e-
H2 + 2OH- --> 2H2O + 2e-
H2O2 + 2H+ + 2e- --> 2H2O
SO4 + 4H+ + 2e- --> H2SO3 +H2O

Which half-reaction will take place at the cathode during the electrolysis of molten KF?
2F- --> F2 + 2e-
K --> K+ + e-
K+ + e- --> K
F2 + 2e- --> 2F-

Which half-reaction will take place at the anode during the electrolysis of 0.10M aqueous KF solution?
O2 + 4H+ + 4e- --> 2H2O
2H2O --> O2 + 4H+ + 4e-
F2 + 2e- --> 2F-
2H2O + 2e- --> H2 + 2OH-

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