5 moles of SO and 5 moles of O are allowed to react. At equilibrium, it was found that 60% of SO is used up. If the total pressure of the equilibrium mixture is one atmosphere, the partial pressure of is (KCET 2009)

2 2 3 1 SO + O SO 2 Initial 5 5 0 Equilibrium 2 3.5 3 2 2 3 [ SO ] 5 5(0.6) 2moles [ O ] 5 5(0.3) 3.5moles [ SO ] 5(0.6) 3moles Total moles will be 2 3.5 3 8.5moles The mole fraction of 2 3.5 O = 8.5 The total pressure at equilibrium is 1 atm 2 O 3.5 P = (1) = 0.41atm 8.5