What is the total number of liters of SO3 produced when 32.0 of SO2 reacts completely

Write the chemical equation for reaction

that is

2SO2+O2 - - - >2SO2

find the moles of SO2 used = moles=mass/molar mass of so2

= 32g/80g/mol=0.4 moles

by use of reacting ratio between SO2 and SO3 which is 2:2 therefore the moles of so3 is also = 0.4 moles

STP 1 mole = 22.4L.

what about 0.4moles

= 0.4 / 1 x22.4=8.96 liters