2-methylpropene reacts with dilute H2SO4 to undergo hydration, forming tert-butyl alcohol as the major product (X).
The reaction is:
CH2=C(CH3)2dil. H2SO4(CH3)3C−OH
Product (X) is an alcohol, which is significantly more polar than the starting alkene due to the presence of the −OH group. In normal phase chromatography, the stationary phase (such as silica gel) is highly polar. The polar −OH group forms strong hydrogen bonds with the stationary phase, causing the alcohol to be adsorbed more strongly than the non-polar alkene.
Consequently, the alcohol travels a shorter distance along the chromatography plate, resulting in a lower Rf value compared to the alkene.
Since the Rf value of 2-methylpropene is 0.42, the Rf value of product (X) must be less than 0.42. Among the given choices, only 0.12 satisfies this condition.
Answer: 0.12