E. a student loaded their mixture of acetylferrocene and diacetylferrocene onto a column using 5 ml of dichloromethane as the loading solvent. they used about 7 g of sio2 as the stationary phase. the student then eluted the column using petroleum ether. after collecting 8 fractions, the student analyzed them by tlc to find that all of the compounds came off in the first two fractions, with no separation. where did the student go wrong, and what should they do differently when they try the column