Question

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 $c{{m}^{3}}$ of ethene is burnt, what is the volume of oxygen gas consumed in the reaction?

Answer 1

Combustion is a high-temperature exothermic redox chemical process that generates oxidised, typically gaseous compounds in a mixture known as smoke. Because a flame is only visible when components undergoing combustion vaporize, combustion does not always result in fire, but when it does, a flame is a distinctive indication of the process. While the activation energy must be overcome to begin combustion (for example, lighting a fire with a lighted match), the heat from a flame may supply enough energy to keep the process going.

Complete answer:
Alkenes can burn, although they are less likely to burn fully than alkanes. If there is enough oxygen available, complete burning of alkenes generates carbon dioxide and water. When oxygen is scarce, incomplete combustion of alkenes occurs, resulting in the production of water, carbon monoxide, and carbon dioxide (soot). The result is a hazy flame.
Ethene is incompletely burned, resulting in carbon dioxide, carbon monoxide, and water vapour. This incomplete combustion reaction's balanced equation is as follows.
$C_{2} H_{4}(g)+\dfrac{5}{2} O_{2}(g) \rightarrow C O_{2}(g)+C O(g)+2 H_{2} O(g)$
But according to the given question the ratio of the volumes of $\mathrm{CO}_{2}(\mathrm{~g}): \mathrm{CO}(\mathrm{g})$ produced is given as 9: 1. So it also represents a mole ratio of $\mathrm{CO}_{2}(\mathrm{~g}): \mathrm{CO}(\mathrm{g})$ amount produced.
As a result, modifying this ratio balanced equation is as follows:
$10 C_{2} H_{4}(g)+\dfrac{39}{2} O_{2}(g) \rightarrow 9 C O_{2}(g)+C O(g)+20 H_{2} O(g)$
Here we see $10 \mathrm{~cm}^{3} \mathrm{C}_{2} \mathrm{H}_{4}(g)$ will require $\dfrac{39}{2}=19.5 \mathrm{~cm}^{3} \mathrm{O}_{2}(g)$
As a result, the needed amount of oxygen to burn $x \mathrm{~cm}^{3}$ ethene will be $\dfrac{19.5}{10} \times x \mathrm{~cm}^{3}=1.95 x \mathrm{~cm}^{3}$

Note:
Natural fires are started by lightning strikes or volcanic materials. Combustion is still the most common way for people to generate energy. Carbon, hydrocarbons, or more sophisticated combinations, such as wood containing partly oxidised hydrocarbons, are commonly used as fuels. The thermal energy produced by the burning of fossil or renewable fuels, such as firewood, is used for a variety of purposes, including cooking, power generating, and industrial or home heating. Combustion is also the sole reaction that currently powers rockets.