MolSynapsequestion bank
MolSynapse / Question bank / General Organic Chemistry II: Acids and Bases / Ortho effect and solvent effects
JEE Advanced levelOne or more correct optionsDifficulty 3 of 3g2216

Which of the following statements about alcohols are correct?

  1. AIn the gas phase, tert-butyl alcohol is more acidic than methanol
  2. BIn aqueous solution, methanol is more acidic than tert-butyl alcohol
  3. CThe reversal of order between gas phase and water is due to the solvation of the alkoxide ions in water
  4. DIn the gas phase, the effect of alkyl groups makes tert-butyl alcohol less acidic than methanol

Answer: A, B, C

In the gas phase the polarisability of larger alkyl groups stabilises the alkoxide, so tert-butyl alcohol is more acidic (A). In water, the small methoxide is better solvated, so methanol is more acidic (B), and this solvation explains the reversal (C). In the gas phase the observed order is opposite to that predicted from the effect alone, so (D) is wrong.
Practice General Organic Chemistry II: Acids and Bases More on Ortho effect and solvent effects
Previous questionNext question

More questions on Ortho effect and solvent effects