The number of litres of air required to burn 8 litres of C2H2 is approximately?

1 Answer
Jun 3, 2017

Answer:

We need a stoichiometric equation, ...................and get an approx. volume of #100*L# air.........

Explanation:

We need a stoichiometric equation to represent the combustion:

#HC-=CH(g) + 5/2O_2(g) rarr2CO_2(g) +H_2O(l)#

And thus given that at constant pressure, and constant temperature (conditions that must be reasonably assumed!), one volume of acetylene gas requires #5/2# volumes of dioxygen for complete combustion..........

And so, if there are #8*L# of acetylene, we requires a volume of #8*Lxx5/2=??L# dioxygen gas.........

But we are not finished there (says he, finally reading the question!). The percentage of oxygen in air BY volume, is approx. #21%#.

And thus we need a volume of ....

#(20*L*O_2)/(0.21*L*O_2*L^-1*"air")~=100*L*"air"#.........