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3 (a) Hydrogen and oxygen are reactants in some fuel cells - Edexcel - GCSE Chemistry - Question 3 - 2021 - Paper 1
Question 3
3 (a) Hydrogen and oxygen are reactants in some fuel cells. Which word equation shows the overall reaction that occurs in these fuel cells? A hydrogen + oxygen → hy... show full transcript
Worked Solution & Example Answer:3 (a) Hydrogen and oxygen are reactants in some fuel cells - Edexcel - GCSE Chemistry - Question 3 - 2021 - Paper 1
Step 1
Step 2
Describe what you would see happen when the torch is turned on and then left for many hours.
Answer
When the torch is turned on, it will illuminate. However, if left on for many hours, the battery may deplete, causing the torch to eventually dim or turn off due to insufficient power from the chemical cell.
Step 3
Step 4
Explain why covering iron tools with a thin layer of grease prevents rusting.
Answer
Covering iron tools with a thin layer of grease creates a barrier that prevents moisture and oxygen from contacting the iron. Since rusting occurs when iron reacts with water and oxygen, this barrier effectively slows down the oxidation process.
Step 5
Explain how the zinc protects the iron from rusting.
Answer
Zinc protects iron through a process known as sacrificial anode protection. When zinc is connected to iron, it serves as a sacrificial metal that corrodes in place of the iron. Zinc is more reactive than iron, so it oxidizes first, thereby preventing the rusting of the iron structure.