Question

which reactant will react slowest and which will react fastest in the reaction shown? R−X +CN gives R−CN + X
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Answer 1

Answer:

Methyl iodide will react faster than methyl bromide towards bimolecular nucleophilic substitution reaction with hydroxide ion. This is because iodide ion is a better leaving group than bromide ion as bigger iodide ion can easily accommodate the negative charge. Also, the C−I bond is weaker than the C−Br bond.