Chemistry - Halogen Derivative Question with Solution | TestHub
NBS (N-bromosuccinimide) is a chemical reagent used in organic chemistry for various bromination reactions. It is a source of bromine radicals and is particularly useful for allylic and benzylic bromination.
One of the most common reactions involving NBS in which performs allylic or benzylic bromination typically proceeds via a free-radical mechanism.
For example, the bromination of propene with NBS can be represented as:
In this reaction, a hydrogen atom on the allylic carbon (the carbon adjacent to the double bond) is substituted by a bromine atom.
Lindlar's reagent is a heterogeneous catalyst that consists of palladium deposited on calcium carbonate (CaCO₃) or barium sulfate (BaSO₄), poisoned with lead acetate (Pb(CH₃COO)₂) and quinoline.
Its primary use is in the selective hydrogenation of alkynes to cis-alkenes. The "poisoning" agents (lead acetate and quinoline) reduce the activity of the palladium catalyst, preventing the further reduction of the alkene to an alkane. This makes Lindlar's reagent a highly selective catalyst for partial hydrogenation.
Molecular weight of B is M report your answer as M/14 .