Q. Which of the following is an iron ore ?

The correct answer is: c) Limonite

Explanation:

Iron ores are minerals from which iron can be extracted. Among the given options:

a) Cinnabar: This is not an iron ore. It is a mineral of mercury (HgS) and is used as a source of mercury.

b) Bauxite: This is not an iron ore. It is the primary ore of aluminum and contains aluminum oxide.

c) Limonite: This is an iron ore. It is a mixture of hydrated iron(III) oxide-hydroxides and is one of the sources of iron.

d) Pyrite: Although pyrite (FeS2) contains iron, it is not considered an iron ore because it is primarily used for sulfur extraction and not for obtaining iron.