There is a redox reaction with the 2 pairs as follows SO2 goes to HSO4- I2 goes to 2I- What is the overall redox equation?

Answer 1

When they ask that kind of question they usually say if its on an acidic or basic medium. Let's do it for acidic (it's almost the same anyway):

Some rules:

>When you need oxigens, add water

>When you need hydrogens, you add H+ in acidic medium and HO-in basic medium

>When you need to balance the charges, add electrons.

Considering those rules:

I2 --> 2I- + 2e-

SO2 --> HSO4-

We need 2 oxygens on the left side so

2H2O + SO2 --> HSO4-

Now we need 3 hydrogens on the right side

2H2O + SO2 --> HSO4- + 3H+

Now two electrons on the left side to balance the charges

2e- + 2H2O + SO2 --> HSO4- + 3H+

Now you add both and cut the 2 electrons from each side giving the overall redox equation:

I2 + 2H2O + SO2 --> 2I- + HSO4- + 3H+

Answer 2

The overall redox reaction is: SO2 + 2I2 + 2H2O -> HSO4- + 4I- + 4H+.