Question

The value of ΔG∘′ for this reaction is +1.8kcal/mol at 25∘C. In which direction does the equilibrium lie?

A) Forward (products)
B) Reverse (reactants)
C) Equilibrium
D) Cannot be determined

Answer 1

The equilibrium of the reaction with a ΔG°′ of +1.8 kcal/mol at 25°C lies in the direction of the reactants, meaning the reaction is spontaneous in the reverse direction.

Step-by-step explanation:

In thermodynamics, the standard free energy change (\( \Delta G^\circ' \)) serves as a key indicator of a reaction's spontaneity. A positive \( \Delta G^\circ' \) value, such as +1.8 kcal/mol at 25°C, suggests a non-spontaneous reaction in the forward direction but a spontaneous one in reverse. This implies that at equilibrium, the system favors the formation of reactants over products. The concentration of reactants is greater than that of products, signifying a tendency for the reaction to shift towards the reactants at equilibrium.

The positive \( \Delta G^\circ' \) underscores the need for an external energy source to drive the reaction in the forward direction, reinforcing the principle that reactions tend to proceed in the direction that minimizes the free energy.