Answer:
Propane burns in air according to the following equation:
C
3
H
8
+5O
2
→3CO
2
+4H
2
O.
1 mole of propane combines with 5 moles of oxygen.
Volume is directly proportional to the number of moles.
1 cm
3
of propane will combine with 5 cm
3
of oxygen.
Only 20% of air contains oxygen. So 1000 cm
3
of air contains 1000cm
3
×
100
20
=200cm
3
of oxygen.
The volume of propane that is consumed on using 1000 cm
3
of air is
5
200cm
3
=40cm
3
.
