Final answer:
Byproducts in chemical reactions, such as biphenyl, can form due to a range of factors including excessive heat, insufficient stirring, side reactions from impurities, and incorrect pH levels.
Step-by-step explanation:
Byproducts like biphenyl can form in a reaction for several reasons: a) Due to excessive heat, which can increase reaction rates to a point where unwanted side reactions become more probable; b) Due to insufficient stirring, which can result in uneven distribution of reactants leading to unintended reactions; c) Side reactions or impurities in the reactants that can result in different products; and d) Incorrect pH levels which can affect the course of the reaction and the stability of the reactants and products.
It's worth noting that the formation of byproducts like biphenyl can be linked to the kinetic energy and the orientation of the molecules involved in the reaction. If reactants are moving too slowly or if their orientation upon collision is incorrect, they may not have enough kinetic energy to exceed the activation energy for the desired reaction, leading to alternative reactions and resulting in different products. Moreover, environmental factors such as temperature and pH can drastically affect reaction rates and the specificity of reactions, which can be particularly relevant in enzyme-catalyzed reactions.