Question

What is the action of following on 2-methylpropan-2-ol?
(a) 20% h2so4 at 360k
(b) NABr and conc. h2so4

Answer 1

Answer:

a) propene s formed by dehydrogenation

Answer 2

20% H2SO4 when added to 2-methylpropan-2-ol at 360 K produces 2-methyl propene while when NaBr and conc. H2SO4 is added to 2-methylpropan-2-ol, 2-bromo, 2-methyl propane is produced.

• The first case is an example of dehydration reaction , where sulfuric acid acts as a dehydrating agent and eliminate water from the reactant giving rise to an alkene.
• The second case is an example of first order substitution reaction , where the alcoholic group in the reactant is substituted by nucleophilic bromine ion involving a carbocation formation.