Correct option is (A)
The reaction given is a disproportionation reaction where iodine () undergoes both oxidation and reduction. Disproportionation reactions are a type of redox reaction where an element is simultaneously oxidized and reduced.
In the process, iodine gets oxidized from 0 oxidation state (in ) to +5 oxidation state (in ), and reduced from 0 oxidation state (in ) to -1 oxidation state (in ).
The n-factor is the total change in oxidation state per molecule that undergoes the redox reaction. In this case, the n-factor for is 5 (as iodine goes from 0 to +5) and for , it's 1 (as iodine goes from 0 to -1).
Now, to balance the redox reaction, the total increase in oxidation state (total oxidation) must equal the total decrease in oxidation state (total reduction). Hence, the molar ratio of to must be 1:5.
So, the balanced reaction would be:
This equation yields 3 moles of , but the original equation needs to produce 6 moles of , so the entire equation is multiplied by 2:
This tells us that to get 6 moles of , you need 10 moles of . So,