67th B.P.S.C. (Re-Exam) (Pre) 2022
What happens to the weight of iron, when it rusts?
aIncreases for long time✓ Correct
bDecreases then increases
cIncreases then decreases
dRemains same
eNone of the above/More than one of the above
Explanation
When iron rusts, it gets oxidized into hydrated iron oxide (Fe2O3·nH2O). Due to the addition of oxygen during oxidation, the weight of iron increases; but after a long time, due to rusting, the process of iron getting consumed starts. Because of this, the weight of iron will decrease. The Bihar Public Service Commission, in its final answer key, considered option (a) as the answer.
general-science