COMPLETE AND INCOMPLETE COMBUSTION COMPLETE COMBUSTION In a

COMPLETE AND INCOMPLETE COMBUSTION

COMPLETE COMBUSTION • In a combustion reaction, oxygen combines with another substance and releases energy in the form of heat and light. • When oxygen is available in sufficient amounts complete combustion occurs

COMPLETE COMBUSTION • This means that all of the carbon atoms and hydrogen atoms from the hydrocarbon molecules combine with oxygen atoms to form carbon dioxide and water. • WHAT IS A HYDROCARBON? ? – A hydrocarbon is a compound that is composed only of the elements carbon and hydrogen.

COMPLETE COMBUSTION • the general equation of the complete combustion of a hydrocarbon is: Cx. Hy + O 2 –> CO 2 + H 2 O

COMPLETE COMBUSTION • Complete combustion is a more efficient process for generating heat since the flame is mostly heat and little light.

INCOMPLETE COMBUSTION • When a reaction has too little oxygen incomplete combustion is the result. • A bright yellow flame is produced during incomplete combustion. In addition to this, soot and toxic carbon monoxide can also be formed through incomplete combustion

INCOMPLETE COMBUSTION • An example equation of the incomplete combustion of propane is: 2 C 3 H 8 (g) + 7 O 2 (g) 2 C(s) + 2 CO(g) + 2 CO 2(g) + 8 H 2 O (g)

INCOMPLETE COMBUSTION • The products of incomplete combustion include carbon dioxide and water vapour as well as carbon, carbon monoxide or both • Incomplete combustion is a more inefficient process for generating heat since it has less oxygen and therefore more light is produced rather than heat. This will be seen with a more yellow flame.

Carbon Monoxide • Why is the formation of carbon monoxide a serious concern? Carbon monoxide is a toxic gas that is both colourless and odourless. Carbon monoxide can bind to oxygen in the blood which will decrease the number of available oxygen binding sites in a person. Symptoms of carbon monoxide poisoning include headache, dizziness, and nausea. Eventually suffocation can be a result of carbon monoxide poisoning. Proper ventilation and the use of carbon monoxide detectors in the home can help to prevent carbon monoxide poisoning.

Complete and Incomplete Combustion using Propane • Propane + oxygen carbon dioxide + water C 3 H 8 (g) + 5 O 2 3 CO 2 + 4 H 2 O • Propane + oxygen carbon + carbon dioxide + water C 3 H 8 (g) + 3 ½ O 2 1 ½ C + 1 ½ CO 2 + 4 H 2 O • Oxygen is limited and therefore carbon is produced as a result.