Glycerol (HO–CH₂–CH(OH)–CH₂–OH) is completely miscible with water. Imagine an idealized sample at 298 K composed solely of glycerol molecules and no solvent.
(a) Calculate the theoretical maximum number of hydrogen bonds that a single glycerol molecule could participate in simultaneously within the bulk liquid. Distinguish between bonds in which the molecule acts as a donor and those in which it acts as an acceptor.
(b) Real liquid-phase measurements show an average of fewer than six hydrogen bonds per glycerol molecule. Provide two independent, molecular-level reasons that account for the discrepancy between the theoretical maximum from part (a) and the experimental average.