You were asked to examine the protective ability of oxalic acid in preventing the oxidative degradation of vitamin C by catalytic ferric ions. At the beginning of the experiment, you or your partner prepared two solutions containing ascorbic acid. In one of these solutions, oxalic acid was added. Then to each of these solutions, ferric nitrate solution was added. The two solutions were then set aside in open containers. When you titrated a sample from each of these solutions, one containing oxalic acid and one without oxalic acid, which solution should have required more NBS to reach the endpoint?