Final answer:
A 2º alkyl halide can undergo an E2 reaction with a strong base, resulting in the formation of an alkene. With a weak base, an SN2 reaction occurs, leading to the substitution of the halogen atom. Poor nucleophiles are not reactive enough to effectively react with the alkyl halide.
Step-by-step explanation:
When a 2º alkyl halide reacts with a strong base, an elimination reaction occurs, specifically an E2 reaction. In this reaction, the base removes a hydrogen atom from the alkyl halide and takes its place, while the halogen atom leaves. The resulting product will be an alkene. For example, if 2-bromobutane reacts with a strong base like sodium ethoxide, ethene will be formed.
On the other hand, when a weak base is used, a substitution reaction known as an SN2 reaction takes place. In this reaction, the weak base attacks the carbon atom attached to the halogen atom and pushes the halogen atom off. This results in the inversion of stereochemistry at the carbon atom. For instance, if 2-chloropropane is reacted with a weak base like sodium acetate, 2-propyl acetate will be formed.
In the case of a poor nucleophile, the reaction will likely be slow or may not occur at all. A poor nucleophile is not reactive enough to compete with other reactions or effectively attack the alkyl halide. Therefore, the reaction rate will be significantly slower or negligible.