Question

How does changing the alkyl halide from CH₃CH₂Br to (CH₃)2CHBr affect the rate of an E2 reaction?

1) The rate of the E2 reaction will increase
2) The rate of the E2 reaction will decrease
3) The rate of the E2 reaction will remain the same
4) The rate of the E2 reaction cannot be determined

Answer 1

The rate of an E2 reaction will increase when changing the alkyl halide from CH3CH2Br to (CH3)2CHBr because the more substituted alkyl halide stabilizes the transition state more effectively.

Step-by-step explanation:

Changing the alkyl halide from CH3CH2Br to (CH3)2CHBr will affect the rate of an E2 reaction. In an E2 reaction, the reaction rate is influenced by the ability of the base to remove a proton and the stability of the resulting alkene. A more substituted alkyl halide, such as (CH3)2CHBr, will typically undergo an E2 reaction faster than a less substituted one like CH3CH2Br, due to the better stabilization of the transition state and the resulting alkene. Therefore, the rate of the E2 reaction will increase when changing from CH3CH2Br to (CH3)2CHBr.