Chemistry Reference
In-Depth Information
13
Inorganic carbon chemistry
Limestone
Direct uses of limestone
Indirect uses of limestone
Carbon dioxide
Uses of carbon dioxide
Laboratory preparation of carbon dioxide gas
Properties of carbon dioxide gas
Carbonates
Properties of carbonates
Checklist
Additional questions
●
Limestone
As the newspaper article on the left says, limestone
is found in the Peak District, an example being this
gorge on the River Wye in the UK (Figure 13.1). As
well as giving rise to beautiful and varied countryside,
limestone is a very useful raw material.
Limestone is composed of calcium carbonate
(CaCO
3
) in the form of the mineral calcite
(Figure 13.2). Chalk and marble are also made of
calcite which is the second most abundant mineral in
the Earth's crust after the different types of silicates
(which include clay, granite and sandstone).
Chalk is made of the 'shells' of marine algae (that
is, plants). It is a form of limestone. Most other
limestones are formed from the debris of animal
structures, for example brachiopods and crinoids.
Marble is a metamorphic rock made of calcium
carbonate. It is formed when limestone is subjected
to high pressures or high temperatures, or sometimes
both acting together, to create crystals of calcium
carbonate in the rock.
In a typical year, in excess of 500 million tonnes
of limestone are quarried worldwide. Although it is
cheap to quarry, as it is found near the surface, there
are some environmental costs in its extraction.
Environmental Problems in
the Peak District National Park
Local residents have been protesting against
proposals to site a new limestone quarry in the
beautiful Derbyshire Peak District in the UK.
However, limestone is such a useful and sought-
after mineral that demand has encouraged mining
in National Park areas.
Question
1
List the environmental issues which could arise through the
quarrying of limestone.
Figure 13.1
This gorge in the Peak District National Park in the UK is
made from limestone.
