5.6 litre of oxygen at stp contains how many atoms

22.4 litres of a gas indicates 1mole.5.6 litres of the gas indicates 0.25 moles.1mole of O₂ gas contains 2 x Avogadro number of atoms of oxygen.so,0.25 moles of O₂ contains →0.25 x 2 x Avogadro number of atoms of oxygen                                          →0.5 x 6 x 10²³ oxygen atoms                                          →3 x 10²³ oxygen atoms∴ 5.6 litres of Oxygen gas contains 3 x 10²³ oxygen atoms.