At a certain temperature, 0.620 mol of SO3 is placed in a 3.00 L containter. `2SO3 (g) harr 2SO2 (g) + O2 (g)` At equilibrium, 0.130 mol of O2 is present. Calculate Kc.
`2SO_3 harr 2SO_2+O_2`
Initial `[SO_3] = 0.62/3M = 0.2067M`
Let us say xM of `SO_3` has dissociated.
`SO_3:SO_2 = 2:2 = 1:1`
`SO_3:O_2 = 2:1`
So xM of SO_2 and x/2M of O_2 will be produced.
`[SO_3] = 0.2067-x`
`[SO_2] = x`
`[O_2] = x/2`
`K_C = ([SO_2]^2[O_2])/[SO_3]^2`
According to the given data x = 0.13
` K_C = ([0.13]^2[0.13/2])/[0.0767]^2`
`K_c = 0.1867`
So `K_c` for the reaction is 0.1867.