The reaction of sulfur dioxide with oxygen can proceed in both directions. $\text{2SO}_2\text{(g)} + \text{O}_2\text{(g)} \rightleftharpoons \text{2SO}_3\text{(g)}$ $K_c = 280\,\text{mol}^{-1}\,\text{dm}^3$ at $1000\,\text{K}$. For an equilibrium mixture at $1000\,\text{K}$, the sulfur trioxide concentration is $6.00\,\text{mol dm}^{-3}$. The sulfur dioxide concentration is double the oxygen concentration. What is the concentration of sulfur dioxide?
- A$0.175\,\text{mol dm}^{-3}$
- B$0.252\,\text{mol dm}^{-3}$
- C$0.318\,\text{mol dm}^{-3}$
- D$0.636\,\text{mol dm}^{-3}$