Solved UPSC CDS/OTA Question
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Q · Metals and Non-MetalsMedium · 45s
Iron rusts when exposed to air and moisture due to formation of:
TopicMetals and Non-Metals
Question Typemultiple choice
DifficultyMedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
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Rust is hydrated iron(III) oxide, Fe₂O₃·nH₂O.
Final Answer: Option A — Fe₂O₃