Calculate the volume of 320 g of SO2 at stp. (Atomic mass : * = 32 and O = 16).
Gram molar mass of SO2 = 32 + (2 x 16) = 6 g.
No. of in 320 g of SO2 = 320/64 = 5
At STP 1 mole of SO2 occupies 22.4 dm3
5 ***** of SO2 will occupy 5 x 22.4 = 112 dm3
