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How is iron protected from corrosion by sacrificial protection? A - OCR Gateway - GCSE Chemistry - Question 15 - 2022 - Paper 1
Question 15
How is iron protected from corrosion by sacrificial protection? A. Iron is coated in a more reactive metal, like magnesium, which is more readily reduced than iron.... show full transcript
Worked Solution & Example Answer:How is iron protected from corrosion by sacrificial protection? A - OCR Gateway - GCSE Chemistry - Question 15 - 2022 - Paper 1
Step 1
D. Iron is coated in a more reactive metal, like zinc, which is more readily oxidised than iron.
Answer
Iron is protected from corrosion by sacrificial protection when it is coated with a more reactive metal, such as zinc. In this scenario, zinc acts as a sacrificial anode. This means that zinc oxidizes preferentially instead of iron, thus preventing the iron from corroding.
The process works because zinc is more reactive than iron, leading it to lose electrons more readily. As zinc oxidizes, it forms a protective layer, effectively shielding the iron surface beneath from the corrosive effects of moisture and oxygen in the environment. This demonstrates the principle of sacrificial protection, where the more reactive metal serves to protect a less reactive one.