Researchers are trying to distinguish between two competing mechanisms for the…
CHEMISTRY · Single correct · A Level · Chemistry · Introduction to organic chemistry · Introduction to organic chemistry
Problem
Researchers are trying to distinguish between two competing mechanisms for the acid-catalyzed hydration of an alkene. Both mechanisms predict the same overall reaction, but Mechanism A proposes a carbocation intermediate, whereas Mechanism B does not. Which experimental observation would most strongly support Mechanism A over Mechanism B?
(a) Measurement of an overall rate law that is first order in acid concentration.
(b) A markedly faster reaction rate when the hydration is carried out in a highly polar solvent rather than in a non-polar solvent at the same temperature.
(c) Detection of a transient positive charge on the reacting alkene by fast spectroscopic methods.
(d) Isolation of a racemic mixture of chiral alcohol when the starting alkene is planar.