half equations for potassium iodide and sulfuric acid?

Question

concentrated sulfuric acid is added to potassium iodide.
what r the half equations?
and also the overall equations?

i assumed that I2 and SO3/2- ions are the products of the reaction between sulfuric acid and potassium iodide.

i couldnt work it out though
any help please??

Answer 1

2I- ----> I2 + 2e- every time.

Then you can have any or all of the following:

(SO4)2- + 2e- + 4H+ --------> SO2 + 2H2O

(SO4)2- + 6e- + 8H+ -------> S + 4H2O

(SO4)2- + 8e- + 10H+ ------> H2S + 4H2O