1) the value of Kb after the decomposition of sulfur trioxide (S03). 2SO3 (g)--2SO2 (g) +O2 (g) is 1.79 x10^-5 at 350 degree celcius. if SO3 initially at 0.200 atm pressure comes to equilibrium in an otherwise empty tank at 350 degree celcius, determine the partial pressure of O2 at equilibrium.