This reaction is very dangerous and should not be repeated.
In this video Sodium metal is reacted with oxygen gas to form Sodium Peroxide. The reaction takes place in 2 steps....
1) 4 Na + O2 → 2 Na2O
2) 2 Na2O + O2 → 2 Na2O2
The reaction of Sodium peroxide and water...
Na2O2 + 3 H2O → 2 NaOH +H2O2