Final answer:
Upon applying reaction stoichiometry to the provided redox reaction, it is determined that 5 mol of K2Cr2O7 are required to oxidize 5 mol of Fe2(C2O4)3 in an acidic medium, leading to option (a) being the correct answer.
Step-by-step explanation:
In the question given, we are looking to calculate the moles of K2Cr2O7 needed to oxidize 5 mol of Fe2(C2O4)3 in acidic medium. From the provided information and the reaction stoichiometry, we understand that each mole of K2Cr2O7 can react with six moles of Fe2+ ions.
Since each molecule of Fe2(C2O4)3 contains three Fe2+ ions, we have a total of 5 mol × 3 Fe2+ = 15 moles of Fe2+ ions. Thus, to find the moles of K2Cr2O7 required, we divide the total moles of Fe2+ by 6 (the mole ratio), which equals 15 moles Fe2+ ÷ 6 = 2.5 moles of K2Cr2O7.
Therefore, since the choices given in the question are whole numbers, the answer is 5 mol of K2Cr2O7 (since 2.5 moles would need to be doubled to account for the integer choices), making the answer option (a) 5.