Chemistry - Using Limestone

Using Limestone

Limestone is used as a building material:

1.       Limestone is a grey/white colour. It is often formed from sea shells and although the original shells are mostly crushed, some fossilised shells remain.

2.       It is quarried out of the ground, which causes some environmental problems.

3.       It is great for making building blocks and often builds buildings such as cathedrals. It is also used for statues and fancy parts of buildings as well.

4.       It is virtually insoluble in plain water, but acid rain is a big problem. The limestone reacts with the acid and it dissolves it away.

5.       It can also be crushed up into chippings and used in road surfaces.

Limestone is mainly calcium carbonate:

1.       Limestone is mainly calcium carbonate – CaCO3.

2.       When it is heated it thermally decomposes to make calcium oxide (quicklime) and calcium dioxide.

3.       When other carbonates are heated, they decompose in the same way.

Quicklime reacts with water to produce slaked lime:

1.       When you add water to quicklime you get slaked lime. Slaked lime is actually calcium hydroxide.

Quicklime + water = slaked lime

2.       Slaked lime is an alkali which can be used to neutralise acid soils in fields. Powdered limestone can be used for this too, but the advantage of slaked lime is that it works much faster.

3.       Slaked lime can also be added to mortar.

Limestone is used…