Question

Iron articles become reddish brown when exposed to air. It is due to the formation of:​

• A. Iron sulphate
• B. Iron oxide
• C. Iron chloride
• D. Iron nitrate

Answer 1

The correct option is B Iron oxide

Iron objects when left open in air, slowly react with oxygen to form a reddish-brown layer of iron oxide on the metal surface.

The chemical equation is given as:
4 Fe (s) + 3 $O_2$ (g) + 2x $H_{2}O$ (l) → 2 ${Fe}_2{O}_3$.x$H_{2}O$ (s)