We've said that the +1 oxidation state is uncommon for indium but is the most stable state for thallium. Verify this statement by calculating E ° and ΔG ° (in kilojoules) for the disproportionation reaction
3 M+1aq2S M3+1aq2 + 2 M1s2 M = In or Tl
Is disproportionation a spontaneous reaction for In+ and/orTl+? Standard reduction potentials for the relevant halfreactions are
In3+1aq2 + 2 e- S In+1aq2 E° = -0.44 V
In+1aq2 + e- S In1s2 E° = -0.14 V
Tl3+1aq2 + 2 e- S Tl+1aq2 E° = +1.25 V
Tl+1aq2 + e- S Tl1s2 E° = -0.34 V