Question

PLEASE I NEED HELP NOW!!! I WILL GIVE 25 POINTS

Balance the following redox equation, identifying the element oxidized and the element reduced. Show all of the work used to solve the problem.

Cr2O72- + I-yields Cr3+ + I2

Answer 1

If I did this correctly the balanced equation would be:
14H⁺+Cr₂O₇²⁻+6I⁻→3I₂+2Cr³⁺+7H₂O

oxidation half: (iodide was oxidized)
2I⁻→I₂+2e⁻

reduction half: (chromium was reduced)
14H⁺+Cr₂O₇²⁻+6e⁻→2Cr³⁺+7H₂O

H⁺ comes from the solution. It is in the final reaction since in redox reactions the oxygen is turned into water since it can't just go away. I multiplied the oxidation half reaction by 3 in order for both half reactions to half the same number of electrons since equal numbers of electrons need to be lost and gained for the reaction to be balanced.

I hope this helps. Let me know if anything is unclear.