Question

In the reaction \( \mathrm{N_2(g)} + 3\mathrm{H_2(g)} \leftrightarrow 2\mathrm{NH_3(g)} \), if the equilibrium constant \( K_c = 4 \times 10^{-3} \) at a certain temperature, which of the following is true about the reaction at equilibrium?

• A. Reactants are favored over products
• B. Products are favored over reactants
• C. Reactants and products are equally favored
• D. Reaction does not reach equilibrium

Hint:

Small \( K_c \) means reaction favors reactants at equilibrium.

Answer 1

The Correct Option is A

The reaction in question is: \(\mathrm{N_2(g)} + 3\mathrm{H_2(g)} \leftrightarrow 2\mathrm{NH_3(g)}\). The equilibrium constant \(K_c\) is given as \(4 \times 10^{-3}\) at a certain temperature. To determine which species is favored at equilibrium, we need to analyze the value of \(K_c\). 

Step-by-step analysis:

1. The equilibrium constant \(K_c\) is defined by the expression:
   \(K_c = \frac{[\mathrm{NH_3}]^2}{[\mathrm{N_2}][\mathrm{H_2}]^3}\), where the square brackets denote the molarity of the substances.
2. A \(K_c\) value much less than 1 (\(K_c \ll 1\)) indicates that the concentration of reactants is greater than that of products at equilibrium. Conversely, a \(K_c\) value much greater than 1 (\(K_c \gg 1\)) suggests that the concentration of products is greater than that of reactants at equilibrium.
3. In this case, \(K_c = 4 \times 10^{-3}\), which is significantly less than 1. This means the equilibrium position lies towards the reactants side, indicating that reactants are favored over products.

Conclusion:

The correct option is: "Reactants are favored over products". The low \(K_c\) value supports this conclusion as it signifies that, at equilibrium, the concentration of reactants will be higher than that of products.

Answer 2

To determine whether reactants or products are favored at equilibrium, we need to analyze the given equilibrium constant \( K_c \) for the reaction:

\( \mathrm{N_2(g)} + 3\mathrm{H_2(g)} \leftrightarrow 2\mathrm{NH_3(g)} \)

The equilibrium constant \( K_c \) is given as \( 4 \times 10^{-3} \).

Key points to consider:

• If \( K_c > 1 \), the products are favored at equilibrium.
• If \( K_c < 1 \), the reactants are favored at equilibrium.
• If \( K_c = 1 \), reactants and products are equally favored.

Since \( K_c = 4 \times 10^{-3} \) is less than 1, this indicates that the equilibrium mixture contains more reactants than products. Therefore, the reaction favors reactants over products at equilibrium.

Correct statement: Reactants are favored over products.