Predict which of the following reaction will have appreciable concentration of reactants and products : a) Cl2 (g) = 2Cl (g) Kc = 5 ×10–39 b) Cl2 (g) + 2NO (g) = 2NOCl (g) Kc = 3.7 × 108 c) Cl2 (g) + 2NO2 (g) = 2NO2Cl (g) Kc = 1.8

To determine which of the given reactions will have appreciable concentrations of both reactants and products, we need to analyze the equilibrium constants (Kc) provided for each reaction. The equilibrium constant gives us insight into the extent to which a reaction favors the formation of products versus reactants at equilibrium. A larger Kc value indicates that the products are favored, while a smaller Kc value suggests that the reactants are favored.

Analyzing Each Reaction

Reaction A: Cl2 (g) = 2Cl (g)

The equilibrium constant for this reaction is Kc = 5 × 10^-39. This value is extremely small, indicating that at equilibrium, the concentration of reactants (Cl₂) will be much greater than that of the products (Cl). In practical terms, this means that very little Cl is formed, and the reaction heavily favors the reactants. Therefore, we can conclude that this reaction will not have appreciable concentrations of products.

Reaction B: Cl2 (g) + 2NO (g) = 2NOCl (g)

For this reaction, Kc = 3.7 × 10⁸. This is a large value, suggesting that the formation of products (NOCl) is favored significantly. At equilibrium, we can expect that the concentrations of both Cl₂ and NO will be relatively low, while the concentration of NOCl will be quite high. Thus, this reaction will have appreciable concentrations of both reactants and products, with a strong tendency towards the products.

Reaction C: Cl2 (g) + 2NO2 (g) = 2NO2Cl (g)

The equilibrium constant for this reaction is Kc = 1.8. This value is moderate, indicating that neither the reactants nor the products are overwhelmingly favored. At equilibrium, we can expect a more balanced concentration of both reactants (Cl₂ and NO₂) and products (NO₂Cl). Therefore, this reaction will also have appreciable concentrations of both reactants and products, though not as strongly skewed towards the products as in Reaction B.

Summary of Findings

• Reaction A: Kc = 5 × 10^-39 - favors reactants, negligible products.
• Reaction B: Kc = 3.7 × 10⁸ - favors products, appreciable concentrations of both.
• Reaction C: Kc = 1.8 - moderate favoring, appreciable concentrations of both.

In conclusion, the reactions that will have appreciable concentrations of both reactants and products are Reaction B and Reaction C. Reaction A, with its extremely low Kc, will predominantly consist of reactants with negligible product formation.

To determine which of the given reactions will have appreciable concentrations of both reactants and products, we need to analyze the equilibrium constants (Kc) provided for each reaction. The equilibrium constant is a measure of the extent to which a reaction proceeds to form products at equilibrium. A large Kc value indicates that the products are favored, while a small Kc value suggests that the reactants are favored.

Analyzing the Reactions

Reaction A: Cl2 (g) = 2Cl (g)

The equilibrium constant for this reaction is Kc = 5 × 10^-39. This value is extremely small, indicating that at equilibrium, the concentration of the reactants (Cl₂) will be much greater than that of the products (Cl). In practical terms, this means that very little Cl is formed, and the reaction heavily favors the reactants.

Reaction B: Cl2 (g) + 2NO (g) = 2NOCl (g)

For this reaction, Kc = 3.7 × 10⁸. This is a large value, suggesting that the formation of products (NOCl) is favored significantly. At equilibrium, we can expect to find appreciable concentrations of both the reactants (Cl₂ and NO) and the product (NOCl), but the products will be present in much higher concentrations compared to the reactants.

Reaction C: Cl2 (g) + 2NO2 (g) = 2NO2Cl (g)

The equilibrium constant here is Kc = 1.8. This value is moderate, indicating that there will be a balance between the concentrations of reactants and products. While products will be formed, there will still be a significant amount of reactants present at equilibrium, making this reaction more balanced compared to the first reaction.

Comparative Summary

• Reaction A: Kc = 5 × 10^-39 - Reactants favored, negligible products.
• Reaction B: Kc = 3.7 × 10⁸ - Products favored, appreciable concentrations of both.
• Reaction C: Kc = 1.8 - Balanced concentrations of reactants and products.

Conclusion

Based on the analysis of the equilibrium constants, Reaction B (Cl₂ + 2NO = 2NOCl) will have appreciable concentrations of both reactants and products due to its large Kc value. Reaction C will also have a reasonable balance, while Reaction A will predominantly consist of reactants with negligible product formation.