## Chemistry and Chemical Reactivity (9th Edition)

$K=279.1$
The equilibrium constant is given by: $K=[SO_3]^2/[SO_2]^2[O_2]$ $K=(4.13\times10^{-3}\ M)^2/(3.77\times10^{-3}\ M)^2(4.30\times10^{-3}\ M)$ $K=279.1$