Atomic mass of Oxygen= 16g
So 16 g of oxygen contains = N atoms of Oxygen.
{ N= Avagadro number= 6.022 x 10²³}
So 8 g of Oxygen contains= N/2 ATOMS of Oxygen
=6.022x10²³/2
= 3.011 x10²³ atoms
Number of moles of O
2
=
32
8
=
4
1
=0.25
Volume of 1 mol of O
2
at STP =22.4 L
∴ Volume of 0.25 mol of O
2
at STP =22.4×0.25=5.6 L