Unbalanced equation prevents clear redox analysis

Steps:

• Identify oxidation states: Cr in CrO₄²⁻ is +6; Cr in Cr₂O₇²⁻ is +6; Cr in Cr³⁺ is +3.
• Check atom balance: Left has 3 Cr atoms; right has 5 Cr atoms (4 from 2Cr₂O₇²⁻ + 1 from Cr³⁺).
• Check charge balance: Left is +2; right is -1.
• Conclude equation is invalid for redox analysis, as atoms and charge do not balance.

Why B is correct:
Not enough information; unbalanced equation invalidates statement.

Why the others are wrong:

• A: Unbalanced equation prevents identifying moles reduced.
• C: Electron transfer cannot be determined from invalid equation.

Final answer: Not enough information.