Ethene undergoes incomplete combustion to form carbon dioxide, carbon monoxide and water vapour. If the ratio of carbon dioxide to carbon monoxide formed is 9:1 when x cm^3 of ethene is burnt, what is the volume of oxygen gas consumed in the reaction?

1 Answer
May 29, 2017

Ethene undergoes incomplete combustion to form carbon dioxide, carbon monoxide and water vapour. The balanced equation of this incomplete combustion reaction is as follows.

C2H4(g)+52O2(g)CO2(g)+CO(g)+2H2O(g)

But as per question the ratio of volumes of CO2(g):CO(g) produced is 9:1. So this also represents the mole ratio of
CO2(g):CO(g) produced.

Hence adjusting this ratio balanced equation may be written as follows
10C2H4(g)+392O2(g)9CO2(g)+CO(g)+20H2O(g)

Here we see 10cm3 C2H4(g) will require 392=19.5cm3O2(g)

So to burn xcm3 ethene the required volume of oxygen will be 19.510×xcm3=1.95xcm3