The gas-phase equilibrium of the oxidation of sulfur dioxide, shown here, has an equilibrium constant, K_p, value of 4.17 $\times$ 10² at 200 $\circ$ C. If a closed vessel was filled with sulfur trioxide and the initial pressure of SO₃ was 0.033 atm at 200 $\circ$ C, what would be the final partial pressure of SO₃? 2SO₂(g) + O₂(g) 2SO₃(g)

Question

Quizplus · Accepted Answer

Since the equilibrium constant is large, it indicates that the reaction heavily favors formation of product, which is sulfur trioxide. Therefore, as the reaction proceeds, greater amounts of product will be formed, causing the partial pressure of sulfur trioxide to increase and the partial pressures of sulfur dioxide and oxygen to decrease. Therefore, the final partial pressure of sulfur trioxide will be greater than the initial partial pressure of sulfur trioxide of 0.033 atm. Hence, the best choice is B, less than 0.033 atm.

The Gas-Phase Equilibrium of the Oxidation of Sulfur Dioxide, Shown ×\times×

The Gas-Phase Equilibrium of the Oxidation of Sulfur Dioxide, Shown $\times$