Question

Classify each reaction as a substitution, an elimination, or neither. Identify the leaving group in each reaction, and the nucleophile in substitutions.

Short answer

(a) Substitution reaction. Here leaving group is bromine and the nucleophile is methoxide ion (^-OCH₃)

(b) Elimination reaction. Here leaving group is a water molecule.

(c) Elimination reaction. Here leaving group is bromine.

Step-by-step solution

Step 1: Definition of Substitution reaction and Elimination reaction.

In a Substitution reaction, the functional group of one chemical compound is substituted by other groups.

In an Elimination reaction, several atoms or groups are removed from the molecule.

Step 2:

(a)is an example of aSubstitution reaction, here Br atom is substituted by OCH₃ group.

Step 3:

(b)is an example of anElimination reaction, here water (H₂O) molecule is removed.

Step 4:

(c)is an example of anElimination reaction, here bromine molecule is removed.