Question

how do the structures of the alkyl groups in the haloalkanes affect each reaction?

Answer 1

The reactivity of haloalkanes in the reactions such as nucleophiliv substitution reactions are determined by the structure of their substituent alkyl groups. The more bulky alkyl groups are, the less reactive alkyl halide is towards SN1 reaction. The reason is the steric hinderance that prevents the attack of incoming nucleophile.

The bulkier alkyl groups increase the reactivity of alkyl halides in SN1 reaction where the formation of tertiary carbocation is favoured.