Q. 11 P - Organic Chemistry (Mcmurry)

Question

Which reaction is likely to be more exergonic, one with ${\mathbf{K}}_{\mathbf{eq}}$=1000 or one with  ${\mathbf{K}}_{\mathbf{eq}}$= 0.001?

Step-by-Step Solution

Answer

The reaction in which ${\mathrm{K}}_{eq}$=1000 is more exergonic.

Step 1: Spontaneous reaction

Reactions that proceed without an external energy supply are called a spontaneous reaction.

For a reaction to be spontaneous, it needs to have a negative value of Gibbs free energy.

Also, for the reaction to be spontaneous, the value of  needs to be positive

Step 2: Relation between K eq and exergonic reaction

When ${\mathrm{K}}_{\mathrm{eq}}$ greater than 1, the energy is out in the reaction,which means the reaction is exergonic.

When ${\mathrm{K}}_{\mathrm{eq}}$  is less than 1, the energy is out in the reaction,which means the reaction is endergonic.

The above reaction  ${\mathrm{K}}_{\mathrm{eq}}$=1000, is more exergonic.