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The composition of the atmosphere changes when fossil fuels are burned in air - Edexcel - GCSE Chemistry - Question 6 - 2012 - Paper 1
Question 6
The composition of the atmosphere changes when fossil fuels are burned in air. When methane undergoes complete combustion carbon dioxide and water are formed. Writ... show full transcript
Worked Solution & Example Answer:The composition of the atmosphere changes when fossil fuels are burned in air - Edexcel - GCSE Chemistry - Question 6 - 2012 - Paper 1
Step 1
Write the word equation for the complete combustion of methane.
Answer
The complete combustion of methane can be expressed in the following word equation:
Methane + Oxygen → Carbon Dioxide + Water
This equation illustrates that when methane burns in the presence of sufficient oxygen, it produces carbon dioxide and water.
Step 2
Describe some of the problems caused by these products.
Answer
The incomplete combustion of methane produces carbon and carbon monoxide, each of which poses significant risks:
- Carbon (Soot): This black substance can accumulate in the environment, leading to air pollution and respiratory issues. It contributes to the dirtying of surfaces and hinders photosynthesis in plants by coating their leaves.
- Carbon Monoxide: This gas is toxic to humans and animals as it binds with hemoglobin in red blood cells, reducing the blood's capacity to carry oxygen. Exposure can lead to symptoms such as headaches, dizziness, and in severe cases, can be fatal.
Step 3
Describe how impurities in fossil fuels result in the formation of acid rain.
Answer
Fossil fuels contain impurities, such as sulfur. When these fuels are burned, they release sulfur into the air:
- Burning in Air: The sulfur reacts with oxygen to form sulfur dioxide.
- Formation of Acidic Fumes: The sulfur dioxide can react with water vapor in the atmosphere to form sulfuric acid, contributing to acid rain.
- Dissolves in Rain Water: This acid rain can harm aquatic ecosystems, damage vegetation, and corrode buildings and structures.