When you measured out one ml of the trans-1,2-dibenzoylethylene in ethyl acetate solution it had a mass of 0.890 grams. (0.050 g of yellow solidand rest of it is ethyl acetate). the forerun of ethyl acetate had a mass of 0.075g and the rest of the ethyl acetate collected had a mass of 0.253 g. the trans-1,2-dibenzoylethylene had a mass of 0.046 g. what is the percent recovery of each of the materials?
if the ethyl acetate collected in the forerun had a refractive index of 1.3715 at 24.5 c, what is the corrected value for 20 c?
3. i. the ir spectrum of trans-1,2-dibenzoylethylene has a strong peak near 1680 cm-1. to what stretching frequency could this peak correspond?

ii. similarly, ethyl acetate shows a strong signal at 1730 cm-1. to what stretching frequency could this peak correspond?

iii. explain why the c=o signal in trans-1,2-dibenzoylethylene appears at lower frequency than that

of ethyl acetate.