After recrystallization, TLC tests were run to see if 1,2-diphenylethane-1,2-diol was present in the products. TLC tests are used to determine the number of components in a mixture. The TLC plates tested are displayed in Figure 1. The first TLC plate, on the left of Figure 1, compares the starting material, benzoin, to the crude 1,2-diphenylethane-1,2-diol product. The spot indicating benzoin was larger and had moved across the TLC plate farther, resulting in a larger Rf value, than the spot indicating the crude 1,2-diphenylethane-1,2-diol product. This reveals that benzoin is less polar than 1,2-diphenylethane-1,2-diol. This is due to the carbonyl group that is present in benzoin. 1,2-diphenylethane-1,2-diol obtains an alcohol group in replacement of the carbonyl group on benzoin. This makes the compound more polar and less likely to move across a TLC plate, obtaining a lower Rf value. The second TLC plate, on the right of Figure 1, compares the starting material, benzoin, to the recrystallized 1,2-diphenylethane-1,2-diol product. The spots on the second plate were almost identical to that of the first plate because it is comparing the same compounds. One plate is using crude 1,2-diphenylethane-1,2-diol and the other plate is using purified 1,2-diphenylethane-1,2-diol. Both the crude and recrystallized plates resulted with only one spot in their lane. This confirms that there was only one component in the product, proving that the 1,2-diphenylethane-1,2-diol product was pure.