Suppose you are a scientist studying the reactions of SO₂ and O₂. If you wish to use gas molar concentrations, you must first convert the equilibrium constant K to Kc. At 400 8C, the equilibrium constant K for 2 SO₂(g) + O₂(g) ⇌ 2 SO₃(g) is 3.1 * 10⁴. What is the value of K_c at this temperature?

PLAN Because P° = 1 bar and c° = 1 mol · L^–1, it is sensible to use R expressed in bar and liters, R = 8.3145 * 10^–2 L · bar · K^–1 · mol^–1, and to note that

Then, Eq. 4a can be written as

To use this equation, identify the value of Δn_r for the reaction, convert the temperature to the Kelvin scale, and rearrange it to solve for K_c.

What should you assume? Assume that the gases are ideal.

Transcribed Image Text:

pº Rcº || 1 bar (8.3145 × 10²L-bar.K'mol') × (1 mol·L') = 12.03 K