For the reaction, 2 SO2(g) + O2(g) == 2 SO3(g), at 450.0 K (Kelvin) the equilibrium constant, Kc, has a value of 4.62. A system was charged to give these initial concentrations, (SO3) = 0.254 M and (O2) = 0.00855 M, and (SO2) = 0.500 M. In which direction will it go?

Question

For the  reaction, 2 SO2(g) + O2(g) == 2 SO3(g), at 450.0 K (Kelvin) the equilibrium constant, Kc, has a value of 4.62. A system was charged to give these initial concentrations, (SO3) = 0.254 M and (O2) = 0.00855 M, and (SO2) = 0.500 M. In which direction will it go?

A. to the right
B. to the left 
C. it will remain at the same concentrations
D. not enough data to tell

I think that it will remain the same.

Is this correct?

DrBob222 · Answer

You need to substitute into the Keq expression (called the reaction quotient when you put the INITIAL values in) and compare that with Kc. I don't think D is correct.