Limestone and Building materials

Question 1

Limestone

Answer 1

Mainly composed of calcium carbonate (CaCO3) and is a building material that is quarried from the ground.

Question 2

Thermal decomposition

Answer 2

Using heat to break down molecules such as calcium carbonate.

Question 3

Thermal decomposition of calcium carbonate

Answer 3

Calcium carbonate → Calcium oxide + Carbon dioxide

CaCO3 → CaO + CO2

(Carbonates of magnesium, zinc, copper and sodium decompose in a similar way)

Question 4

Calcium oxide

Answer 4

Produced by the thermal decomposition of calcium carbonate.

Question 5

Calcium hydroxide

Answer 5

An alkali that is produced by adding water to calcium oxide.

Calcium hydroxide + water → Calcium hydroxide

CaO + H2O → Ca(OH)2

Question 6

Limewater

Answer 6

A solution of calcium hydroxide that turns cloudy in the presence of carbon dioxide (because it produces calcium carbonate).

Calcium hydroxide + Carbon dioxide → Calcium carbonate + water

Ca(OH)2 + CO2 → CaCO3 + H2O

Question 7

Cement

Answer 7

Produced when limestone is heated with clay.

Question 8

Mortar

Answer 8

Cement and sand added together (with water)

Question 9

Concrete

Answer 9

Cement, sand and aggregate added together (with water).