100 ml of gaseous hydrocarbon consumes 300

ml of oxygen for the complete combustion.

The hydrocarbon is

a. C2H4

b. C2H2

C. C3H8

d. C2H6

The answer would be a. C2H4 (ethylene)

1C2H4+3O2~>2CO2+2H2O

a. C2H4.

Explanation:

Let's look at the balanced equation for C2H4.

C2H4 + 3O2 - -> 2CO2 + 2H2O

So 1 mole of this hydrocarbon reacts with 3 moles of oxygen and since 1 mole of one gas occupies the same volume as another gas, the volumes will be in the ratio 1:3. So this is the required hydrocarbon.