Biacetyl , C4H6O2, is a keytone used to flaour margarine. This compound contains no rings and no carbon-carbon double bonds. a) What is the structure of biacetyl? b) Indicate the hybridization of each carbon atom. c) How many pi bonds are present? d) Do the four carbon atoms lie in a plane or do they lie in a straight line? Draw the structures of three constitutional isomers of biacetyl, all of which contain no rings and no carbon-carbon bonds. Which of these isomers would you expect to have the highest boiling point? why?