Draw an energy diagram for a two-step reaction with Keq>1 . Label the overall ΔG^∘, transition s

Draw an energy diagram for a two-step reaction with Keq>1 ....

Key Concepts

Equilibrium Constant (K_eq)

The equilibrium constant (K_eq) quantifies the ratio of product concentrations to reactant concentrations at equilibrium. It is directly related to the standard free energy change by the equation ?G° = –RT ln K_eq, with a K_eq greater than one indicating that the products are thermodynamically favored, resulting in a negative ?G°.

Reaction Intermediate

A reaction intermediate is a transient species formed during one step of a multi-step reaction and then consumed in a subsequent step. It is not present in the overall balanced equation but is essential in connecting the individual steps of the complete reaction mechanism.

Standard Free Energy Change (?G°)

The standard free energy change (?G°) measures the overall difference in free energy between reactants and products under standard conditions. Its sign indicates the thermodynamic favorability of a reaction—negative ?G° corresponds to a spontaneous, product-favored reaction, particularly when the equilibrium constant (K_eq) is greater than one.

Reaction Coordinate

The reaction coordinate is an abstract axis that represents the progression of the reaction from reactants to products. Along this axis, various points illustrate the key stages of the reaction, including the transition states and any intermediates, highlighting the sequence and energy barriers involved.

Energy Diagram

An energy diagram is a graphical depiction of the changes in free energy during the progress of a chemical reaction. It plots the energy level of reactants, intermediates, and products along a reaction coordinate, indicating the energy required for each step and helping visualize the activation energies and overall energy change.

Transition States

Transition states represent the highest energy points along the reaction path for each elementary step. They are unstable configurations of atoms during the transformation of reactants into products, and their energy levels correspond to the activation energy required for the respective reaction step.

Transcript

00:01 In this question, we are going to draw an energy diagram for a two -step reaction where the equilibrium constant is greater than one.

00:09 Now let's just write the equation of a general equilibrium reaction.

00:16 So we have the reactants and the products.

00:34 Okay? so the equilibrium constant is equal to the product of the concentration of the products raised to the coefficients.

00:48 In the balance equation, so this is d, c, divided by the concentration of the reactants, raised the coefficients, which is a and b.

01:09 Okay? so in this question, the equilibrium constant is greater than one.

01:23 And when that happens, the forward reaction is energetically more favorable.

01:53 So this means that the formation of the products is favor.

02:19 Okay, so therefore, the reaction is exogonic.

02:37 Okay, and when that happens, the free energy change of the reaction is negative.

02:53 Okay, so if we are going to recall, the free energy change for the reaction, is equal to the free energy of the products minus the free energy of the reactants.

03:19 So for a negative free energy change of the reaction, the free energy, the free energy of the products needs to be less than the free energy of the reactants.

03:44 Okay, so now let's demonstrate this in an energy diagram.

03:55 Okay, so let's draw an energy level where the reactants could be.

04:03 So let's draw it here.

04:11 So this would be the reactants, okay? and the reaction proceeds via two steps.

04:23 So that means you would go through a transition state, a first transition state, to get an intermediate, which would be the first step of the reaction.

04:34 So let's show that.

04:48 So at this point, this is the intermediate...

Please give Ace some feedback