Question

The ore of aluminium is
A.Hematite
B.Magnetite
C.Bauxite
D.Siderite

Answer 1

Ores are those minerals from which metals are extracted conveniently and profitably. There are mainly four types of ores such as oxides, carbonate ores, sulphide and halides Ores. Ores are classified based on how they form. Nickel, copper, and iron ores are typically formed from magmatic or volcanic-related deposits. Carbonate alkaline ores are formed from other igneous processes other than volcanic activity.

Complete answer:
(a) Hematite is also spelled haematite. It is a heavy and relatively hard oxide mineral, ferric oxide ($F{e_2}{O_3}$), that constitutes the most important iron ore because of its high iron content ($70\%$) and its abundance. Hence, haematite is a carbonate ore of iron.

(b) Magnetite is a mineral and another main iron ores, with the chemical formula $F{e_3}{O_4}$. It is one of the oxides of iron. It is attracted to a magnet and can be magnetized to become a permanent magnet itself.

(c) Aluminium is the most abundant metal in the earth's crust. It does not occur in the free state as it is a reactive metal. Ores of aluminium are Bauxite, Cryolite and Corundum. Bauxite is hydrated aluminium oxide having the formula $A{l_2}{O_3}.2{H_2}O$.
(d) Siderite also known as chalybite. It is a widely spreading mineral and ore of iron, with chemical formula $Fe{O_3}$. This mineral commonly occurs in thin beds with shales, clay, or coal seams (as sedimentary deposits) and in hydrothermal metallic veins (as gangue, or waste rock).
Hence, the correct option is (C). Bauxite

Note:
Magnetite and hematite are important minerals that can be used as sources for extraction of iron. The main difference between magnetite and hematite is that magnetite is ferromagnetic whereas hematite is paramagnetic. Painite is the rarest gem mineral on earth.