im so sorry! i did read the guidelines but i guess i skipped over that exact point. thank you.

so i did attempt it a bit on paper but im stuck with the grams part. i know that fe is oxidized to fe3+. i know the charge on an electron is 1.602 x 10^-19 & i have avogadros number but how im supposed to go about solving this has me confused as well as the 115 grams