electrochemistry

1. Mn²⁺ +2H₂O MnO₂ +4H⁺+2e^- E⁰= -1.23
MnO₄^- +4H⁺+3e^- MnO₂+2H₂O E⁰=+1.70

Select correct statement[s]:
a.Mn²⁺ reacts with MnO₄^- in acid solution to form MnO₂
b.Mn(MnO₄)₂ is stable in acid soln.
c.MnO₂ disproportionates to Mn²⁺ and MnO₄^- in acid soln.
d.NOT

2. consider half cell reactions:
H₂O₂O₂+2H⁺+2e^- E⁰=-0.69
H₂O₂ +2H⁺+2e^-2H₂O E⁰=1.77
Fe²⁺Fe³⁺+e^- E⁰=0.771
FeFe²⁺+2e^- E⁰= 0.44
If H₂O₂ is mixed with Fe²⁺, which rxn is more likely
a.Oxidation of Fe²⁺ to Fe³⁺
b.Reduction of Fe²⁺ to Fe
c.Both
d.NOT

3. Cu²⁺+e^-Cu⁺ E⁰=0.15
Cu²⁺+2e^- Cu E⁰=0.34
predict which exists in aqueous soln
a.Copper(I)Sulphate
b.Copper(II)Sulphate
c.Both
d.NOT