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Pentadecane, C₁₅H₃₂, is a hydrocarbon and is used as a fuel - Edexcel - GCSE Chemistry - Question 9 - 2021 - Paper 1
Question 9
Pentadecane, C₁₅H₃₂, is a hydrocarbon and is used as a fuel. (a) The incomplete combustion of pentadecane produces carbon monoxide. Carbon monoxide is a toxic gas. ... show full transcript
Worked Solution & Example Answer:Pentadecane, C₁₅H₃₂, is a hydrocarbon and is used as a fuel - Edexcel - GCSE Chemistry - Question 9 - 2021 - Paper 1
Step 1
Explain why the incomplete combustion of pentadecane can produce carbon monoxide as one of the products.
Answer
Incomplete combustion occurs when there is insufficient oxygen available for the complete conversion of fuel to carbon dioxide and water. In the case of pentadecane (C₁₅H₃₂), if oxygen (O₂) is limited, the hydrocarbon cannot fully oxidize, leading to the formation of carbon monoxide (CO) instead of carbon dioxide (CO₂). The overall reaction can be represented as:
ightarrow ext{CO} + ext{H}_2 ext{O}$$ Inadequate oxygen levels promote the formation of CO, which is a partially oxidized product that results from the hydrocarbon reacting with less oxygen than required for complete combustion.Step 2
Explain how carbon monoxide behaves as a toxic gas.
Answer
Carbon monoxide (CO) is a toxic gas primarily due to its ability to bind with hemoglobin in red blood cells more effectively than oxygen. This competitive binding prevents oxygen from attaching to hemoglobin, leading to decreased oxygen delivery to tissues and organs. The reaction can be demonstrated as:
ightleftharpoons ext{COHb}$$ This formation of carboxyhemoglobin (COHb) can result in symptoms of poisoning such as headache, dizziness, confusion, and at high concentrations, it can be fatal due to hypoxia, where body tissues are deprived of oxygen.