Question

The number of litres of air required to burn 8 litres of C2H2 is approximatelu

Answer 1

Here .
1 mole of C2H2 or any substance will contain 22.4 l

so,
22.4 L------------------1mole
1 L-------------------1/22.4 mole
and then 8L --------------8/22.4mole
I. e 1/2.8mole

So here 1/2.8 mol of oxygen will be required.
volume of air= 1/2.8×6.022×10^23

Answer 2

note to self: The percentage of Oxygen in air by volume, is approx 21%