We are being asked to balance the reaction of dichromate at the cathode and I- at the anode in acid.
lose electrons → oxidation → anode
gain electrons → reduction → cathode
Cathode: Cr2O72-(aq) → Cr3+(aq)
Anode: I-(aq) → I2(aq)
When balancing redox reactions under acidic conditions, we will follow the following steps.
Step 1: Separate the whole reaction into half-reactions
Step 2: Balance the non-hydrogen and non-oxygen elements first
Step 3: Balance oxygen by adding H2O to the side that needs oxygen (1 O: 1 H2O)
Step 4: Balance hydrogen by adding H+ to the side that needs hydrogen (1 H: 1 H+)
Step 5: Balance the charges: add electrons to the more positive side (or less negative side)
Step 6: Balance electrons on the two half-reactions
Step 7: Get the overall reaction by adding the two reaction
Balance the reaction of dichromate at the cathode and I- at the anode in acid. What is the sum of the coefficients of the balanced reaction?
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