Sulfur dioxide and oxygen react in a reversible reaction. $\text{2SO}_2(g) + \text{O}_2(g) \rightleftharpoons \text{2SO}_3(g)$ $K_c = 280\ \text{mol}^{-1}\text{dm}^3$ at $1000\ \text{K}$. For an equilibrium mixture at $1000\ \text{K}$, the concentration of sulfur trioxide is $6.00\ \text{mol dm}^{-3}$. The concentration of sulfur dioxide is twice that of oxygen. Calculate the sulfur dioxide concentration.
- A$0.175\ \text{mol dm}^{-3}$
- B$0.254\ \text{mol dm}^{-3}$
- C$0.318\ \text{mol dm}^{-3}$
- D$0.636\ \text{mol dm}^{-3}$