Thermodynamic and Kinetic Control Practice Test

A reactant R can form two products, P and Q, via two competing pathways. The table compares the pathways qualitatively.

Pathway comparison (qualitative):

• To P: lower activation energy; product P is higher in energy (less stable)
• To Q: higher activation energy; product Q is lower in energy (more stable)

If the reaction is started at low temperature and stopped quickly before significant interconversion can occur, which result is most likely?

In a lab, a reaction can produce two isomeric products, A and B, from the same reactant. The pathway to A has the higher activation energy but leads to the more stable product (lower final potential energy). The pathway to B has the lower activation energy but leads to the less stable product. The reaction mixture is heated for a long time and allowed to reach equilibrium. Which statement best describes what is favored under these conditions?