Question

Which of the following reactions lies to the right, favoring the formation of products, and which lies to the left, favoring formation of reactants? (a) \(2 \mathrm{NO}(g)+\mathrm{O}_{2}(g) \rightleftharpoons 2 \mathrm{NO}_{2}(g) ; K_{p}=5.0 \times 10^{12}\) (b) \(2 \mathrm{HBr}(g) \rightleftharpoons \mathrm{H}_{2}(g)+\mathrm{Br}_{2}(g) ; K_{c}=5.8 \times 10^{-18}\)

Short answer

In conclusion, for reaction (a) with \(K_p = 5.0 \times 10^{12}\), the equilibrium lies to the right, favoring the formation of products. For reaction (b) with \(K_c = 5.8 \times 10^{-18}\), the equilibrium lies to the left, favoring the formation of reactants.

Step-by-step solution

Reaction (a) Analysis

For reaction (a), the given equilibrium constant is: \(K_p = 5.0 \times 10^{12}\) Since \(K_p > 1\), this means that the reaction is product-favored, or the reaction lies to the right. The equilibrium position is towards the formation of products.

Reaction (b) Analysis

For reaction (b), the given equilibrium constant is: \(K_c = 5.8 \times 10^{-18}\) In this case, the equilibrium constant \(K_c < 1\), which means the reaction is reactant-favored, or the reaction lies to the left. The equilibrium position is towards the formation of reactants. In conclusion, reaction (a) lies to the right, favoring the formation of products, and reaction (b) lies to the left, favoring the formation of reactants.