Question

What volume of oxygen at STP is required to affect the combustion of 11 litres of ethylene [C2H4] at 273∘C and 380 mm of Hg pressure?
C2H4+3O2→2CO2+2H2O

Answer 1

Let no. of mole of C2H4 is n
pressure = 380/760 atm = 1/2 atm
T = 273+273 = 546K
V = 11 L
R = 0.0821
apply
PV = nRT
11/2= n*0.0821*546
n = 0.123 mole
for one mole of combustion of C2H4 3mole of O2 is required
so for
0.123 mole = 3*0.123 mole O2 required
= 0.369mole
volume of one mole gas at stp = 22.4L
volume of 0.369 mole O2 at stp = 22.4*0.369 = 8.27L