The equilibrium constant is given for one of two reactions below. Determine the value of the missing equilibrium constant. H₂(g) + Br₂(g) ⇌ 2HBr(g) K = 3.8 × 10⁴
2HBr(g) ⇌ H₂(g) + Br₂(g) K = ?

Question

Quizplus · Accepted Answer

We can use the equation ΔG° = -RT ln(K) to solve for the missing equilibrium constant. First, we need to write the second equation in the opposite direction: H₂(g) + Br₂(g) ⇌ 2HBr(g) 2HBr(g) ⇌ H₂(g) + Br₂(g) We know that ΔG° for the first reaction is -RT ln(3.8 × 10⁴) To find ΔG° for the second reaction, we can use the equation: ΔG°₂ = -ΔG°₁ ΔG°₂ = -(-RT ln(3.8 × 10⁴)) = RT ln(3.8 × 10⁴) Now we can use the equation ΔG° = -RT ln(K) for the second reaction to find K: RT ln(K) = RT ln(3.8 × 10⁴) ln(K) = ln(3.8 × 10⁴) K = 3.8 × 10⁴ Therefore, the missing equilibrium constant is equal to the equilibrium constant for the first reaction, which is 3.8 × 10⁴. The closest choice is C, which is 2.6 × 10^-5, but none of the choices match exactly.

The Equilibrium Constant Is Given for One of Two Reactions