The high-temperature production of sulfur trioxide is an important step in the industrial synthesis of sulfuric acid. Consider the reaction
2SO2(g)+O2(g)⇌2SO3(g)(T=800K)
At this temperature the equilibrium constant is Kc=4.5×102. An engineer introduces the following initial concentrations into a 5.00 L reaction vessel at 800 K:
$\begin{aligned}
[\text{SO}_2]_0 &= 0.200\,\text{mol L}^{-1}
_0 &= 0.100\,\text{mol L}^{-1}
_0 &= 0.350\,\text{mol L}^{-1}
\end{aligned}$
(a) Calculate the reaction quotient Qc for the mixture immediately after the gases are combined.
(b) Compare the value of Qc to Kc and determine the direction in which the net reaction will proceed to establish equilibrium. Explain your reasoning.
(c) On qualitative concentration–time axes, sketch or describe how the concentrations of SO2, O2, and SO3 are expected to change until equilibrium is reached. Clearly indicate which curves correspond to which species and how their slopes evolve as equilibrium is approached.