p0a9wmeliiemillarian p0a9wmeliiemillarian 29-10-2016 Chemistry contestada How do you balance C2H2 + O2 -> CO2 + H2O?? Is it C2H2 + 5/2 O2 -> 2CO2 + H2O or 2C2H2 + 5O2 -> 4CO2 + 2H2O ?