Pure R, R-hydrobenzoin (side product of meso-hydrobenzoin) has a melting point of 148°C. a) What do you expect the melting point of pure S, S-hydrobenzoin (another side product of meso-hydrobenzoin) to be? b) Do you expect the racemic mixtures of these enantiomers to have the same or different melting points as the pure enantiomers?

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.