Calculate the equilibrium constant for the following reaction at 525 K: 2H₂S(g)→ 2H₂(g)+ S₂(g)$\quad$$\quad$Δ_rH° = 169.8 kJ mol^-1; Δ_rS°= 78.0 J K^-1 mol^-1

Question

Quizplus · Accepted Answer

First, we need to calculate the value of ΔS1U1B1rS1U1B0G° (standard Gibbs free energy change) for the given reaction using the formula:

ΔS1U1B1rS1U1B0G° = ΔS1U1B1rS1U1B0H° - TΔS1U1B1rS1U1B0S°

Where T is the temperature in Kelvin, ΔS1U1B1rS1U1B0S° is the standard entropy change and ΔS1U1B1rS1U1B0H° is the standard enthalpy change.

Substituting the given values, we get:

ΔS1U1B1rS1U1B0G° = 169.8 - (525 K × 78.0 × 10S1U1P1-3S1S1P0) = -10,425.5 J molS1U1P1-1S1S1P0

Next, we can use the following formula to calculate the equilibrium constant (K) at the given temperature:

ln K = -ΔS1U1B1rS1U1B0G° / R - ΔH1U1B1rS1U1B0 / RT

Where R is the gas constant, T is the temperature in Kelvin, and ΔH1U1B1rS1U1B0 is the standard enthalpy change.

Substituting the given values, we get:

ln K = -(-10,425.5 J molS1U1P1-1S1S1P0) / (8.314 J K1U1P1-1S1S1P0 molS1U1P1-1S1S1P0 × 525 K) - 0 / (8.314 J K1U1P1-1S1S1P0 molS1U1P1-1S1S1P0 × 525 K)

ln K = 35.871

Taking the exponential of both sides, we get:

K = eS1Z35.871S1P = 1.512 × 10S1U1P1-13S1S1P0

Therefore, the best choice is B.

Calculate the Equilibrium Constant for the Following Reaction at 525 \quad

Calculate the Equilibrium Constant for the Following Reaction at 525 $\quad$