A reaction has an equilibrium constant very much less than 1. Will the reaction proceed spontaneously?
A. Yes, because products are favored and deltaG° < 0.
B. Yes, because reactants are favored and deltaG° > 0.
C. No, because reactants are favored and deltaG° > 0.
D. No, because products are favored and deltaG° < 0.
C. No, because reactants are favored and deltaG° > 0
The correct answer is C. No, because reactants are favored and ΔG° > 0.
The equilibrium constant (K) is a measure of the position of the equilibrium for a chemical reaction. When K is much less than 1, it means that the concentration of the products is much smaller compared to the concentration of the reactants at equilibrium.
If reactants are favored, it means that the equilibrium lies towards the left side of the equation, indicating that the reactants are more predominant than the products. In this case, the reaction will not proceed spontaneously because the Gibbs free energy change (ΔG°) will be positive, indicating a non-spontaneous reaction.
A positive ΔG° value indicates that the reaction requires energy to proceed and is therefore not spontaneous.
To determine whether a reaction will proceed spontaneously, we can look at the sign of the standard Gibbs free energy change (ΔG°) and compare it to the equilibrium constant (K).
The standard Gibbs free energy change, ΔG°, is related to the equilibrium constant, K, by the equation:
ΔG° = -RT ln(K)
where R is the gas constant and T is the temperature in Kelvin.
If the equilibrium constant, K, is very much less than 1, it means that the concentration of products is much smaller compared to the concentration of reactants at equilibrium. In other words, the reactants are favored over the products.
Now, looking at the equation ΔG° = -RT ln(K), we can see that if the equilibrium constant (K) is very small, ln(K) will be a negative value. Therefore, ΔG° will be a positive value.
Since a positive value of ΔG° indicates that the reaction is not spontaneous, the correct answer is:
C. No, because reactants are favored and ΔG° > 0.