Question

select all the correct answers.
in this reaction, how does the rate of forward reaction vary with the concentration of the product?
2h₂s(g) ⇌ 2h₂(g) + s₂(g)

• it increases with an increase in the concentration of s₂(g).
• it decreases with a increase in the concentration of h₂(g).
• it increases with a decrease in the concentration of h₂(g).
• it decreases with an increase in the concentration of s₂(g).
• it decreases with increase in the concentration of h₂(g).

Explanation:

To determine how the forward reaction rate varies with product concentration, we use Le Chatelier's principle. For the reaction \( 2H_2S(g)
ightleftharpoons 2H_2(g) + S_2(g) \), the forward reaction produces \( H_2 \) and \( S_2 \). An increase in product concentration (\( H_2 \) or \( S_2 \)) shifts the equilibrium left, decreasing the forward reaction rate. A decrease in product concentration shifts the equilibrium right, increasing the forward reaction rate.

• "It increases with an increase in \( S_2(g) \)": Incorrect (increase in product slows forward rate).
• "It decreases with a decrease in \( H_2(g) \)": Incorrect (decrease in product increases forward rate, so this statement is wrong).
• "It increases with a decrease in \( H_2(g) \)": Correct (decreasing product \( H_2 \) shifts equilibrium right, increasing forward rate).
• "It decreases with an increase in \( S_2(g) \)": Correct (increasing product \( S_2 \) shifts equilibrium left, decreasing forward rate).
• "It decreases with increase in \( H_2(g) \)": Correct (increasing product \( H_2 \) shifts equilibrium left, decreasing forward rate).

Answer:

C. It increases with a decrease in the concentration of \( H_2(g) \)
D. It decreases with an increase in the concentration of \( S_2(g) \)
E. It decreases with increase in the concentration of \( H_2(g) \)