Join WhatsApp ChannelDaily MCQs & Exam Updates
Chemistry Medium FPSC PPSC NTS Uploaded: 14 Jul 2026

What is the chemical formula for rust formed on iron?

  • A Fe2O
  • B Fe3O4
  • C FeO
  • D Fe2O3
Correct Answer: Option B — Fe3O4
Explanation:
Rust is hydrated iron oxide with the formula Fe2O3 nH2O formed when iron reacts with oxygen and moisture through an electrochemical oxidation process.
4 views Back to Chemistry
Submitted by: PaperMCQs
Related MCQs