As a result of the reaction, the scheme of which is C2H4 + O2 = CO2 + H2O,

As a result of the reaction, the scheme of which is C2H4 + O2 = CO2 + H2O, 1.5 liters of carbon dioxide were formed. The volume of oxygen reacted (l) is

given:
V (CO2) = 1.5 l
find: V (O2)
decision:
C2H4 + 3O2 = 2CO2 + 2H2O
1) n (CO2) = V / Vm = 1.5 l / 22.4 l = 0.07 mol
2) n (CO2): n (O2) = 1: 1
n (O2) = 0.07 mol
3) V (O2) = 0.07 mol * 22.4 L = 1.5 L
answer: V (O2) = 1.5