2SO2(g)+O2(g)⇌2SO3(g).....(i) K = 278 By revrsing the equation (i),we get 2SO3(g)⇌2SO2(g)+O2(g)....(ii) Equilibrium constant for this reaction is K′=
1
K
=
1
278
By dividing the equation (ii) by 2, we get desired equation SO3(g)⇌SO2(g)+
1
2
O2(g).....(iii) Equilibrium constant for this reaction K′′=√K′=√