Give the direction of the reaction, if K << 1. Neither direction is favored. If the temperature is raised, then the forward reaction is favored. The reverse reaction is favored. If the temperature is raised, then the reverse reaction is favored. The forward reaction is favored.
The Correct Answer and Explanation is:
Correct Answer: The reverse reaction is favored.
When the equilibrium constant KKK is much less than 1, it means that at equilibrium, the concentration of the reactants is significantly higher than that of the products. In other words, the system does not favor the formation of products, and the equilibrium position lies far to the left. This implies that the reverse reaction is favored under standard conditions.
The equilibrium constant KKK is a ratio of the concentrations of products to reactants, each raised to the power of their respective coefficients in the balanced chemical equation. Mathematically, it is given by:K=[products][reactants]K = \frac{[\text{products}]}{[\text{reactants}]}K=[reactants][products]
If K≪1K \ll 1K≪1, then the numerator (product concentrations) is much smaller than the denominator (reactant concentrations). This suggests that the forward reaction, which produces the products, does not proceed to a significant extent. Instead, the system remains largely in the state where reactants dominate.
From a thermodynamic perspective, this situation occurs when the Gibbs free energy change ΔG∘\Delta G^\circΔG∘ for the reaction is positive. A positive ΔG∘\Delta G^\circΔG∘ means the forward reaction is non-spontaneous under standard conditions, and the reverse reaction is more favorable.
It is important not to confuse this condition with the effects of changing temperature. The value of KKK itself depends on temperature, and how it changes depends on whether the reaction is exothermic or endothermic. However, when only considering the magnitude of KKK and it is much smaller than 1, the best conclusion is that the reverse reaction is favored at equilibrium.
