Organic Chemistry help plz!!!?

I followed your link but there was not much detail there and the oxidant being used was KMnO4....Based on what you have written, the teacher is wanting to know why an anion (HCrO4) is sticking to the resin. I am guessing the resin has cations (perhaps NR4+?) so a ion pair would be formed...that is a guess based on little information though.