What will burning of .3 liters of C2H2 produce?
First the chemical equation, combustion of a hydrocarbon yields CO2 and H2O most of the time.
2C2H2(g)+5O2(g) → 4CO2(g) + 2H2O(g)
We see that 2L of C2H2 produces 4L of CO2 and 2L of H2O. However, when cooled to STP, H2O condenses to water (l.)