Hi Natasha,

What is the difference between kinetic and thermodynamic control again?

Kinetic control indicates your reaction product is dictated by activation energy, and not by which product is the most stable in energy, while thermodynamic control the opposite is true, the product that is the most stable will form regardless of activation energy.


And why is kinetic control not irreversible and thermodynamic control is?

It is unusual to refer to control as irreversible, but generally speaking, conditions for kinetic control generally mean that the reaction is irreversible - if the molecule were allowed to equilibrate forward and back you would eventually expect to wind up at the more stable thermodynamic product. When you have a kinetically controlled, irreversible reaction, you can be "kinetically trapped" in a less stable but easier to form product.

In contrast, thermodynamic control generally implies reversible equilibrium is possible in the reaction.

Also, is there such thing as kinetic equilibrium or only thermodynamic equilibrium?

As per the previous answer, the general implication is that kinetic control does not allow equilibration as this would tend to yield the thermodynamic product.

I hope this helps,

Katt