Final answer:
The formation of a mixture of alkenes during a reaction is primarily due to the reactive C=C double bond in alkenes, which allows for different reaction mechanisms and the formation of isomers, leading to a mixture of products.
Step-by-step explanation:
A good reason for the formation of a mixture of alkenes in a reaction based on the lab lecture could be due to the different possible reaction mechanisms that alkenes can undergo.
Since alkenes have a reactive double bond (C=C), when they undergo an addition reaction, the double bond is broken and two new single bonds (σ bonds) are formed.
However, this process can lead to the formation of different isomers because the double bond can be approached from different directions or the reaction can occur at different carbon atoms if there are substituents present, resulting in variability in the products.
Moreover, the starting material could have different geometric or structural isomers, which would react slightly differently. Together with the varying stability of potential intermediates and transition states during the reaction, this leads to a mixture of products rather than a single alkene.
In industrial applications, these differences could affect the cost and efficiency of the process, as some reactions might require more energy than others.