Limestone and Cement Flashcards
What is limestone mainly made up of?
Calcium carbonate
What happens when calcium carbonate is heated?
It breaks down into calcium oxide and carbon dioxide.
What happens when calcium oxide reacts with water?
It produces calcium hydroxide.
What are some of the things Limestone can be used to make?
Cement, Mortar and Concrete
What happens when calcium carbonate is heated strongly?
It breaks down. This reaction is called thermal decomposition.
Which other metal carbonates break down in a similar way to calcium carbonate?
Sodium Carbonate
Magnesium Carbonate
Copper Carbonate
Do metals high up in the reactivity series need a lot of energy or a small amount of energy to decompose them?
A lot of energy.
Do metals low down in the reactivity series need a lot of energy or a small amount of energy to decompose them?
A small amount.
What is calcium hydroxide?
An alkali.
How is limestone produced and what is it used for?
It is quarried and used as a building material.
Why is limestone damaged by acid rain?
Because it is mainly composed of calcium carbonate.
What is calcium hydroxide used for?
It used to neutralise excess acidity.
How is limestone used to make cement, mortar and concrete?
Cement is made by heating powdered limestone with clay.
Mortar is made by mixing cement with water and sand.
Concrete is made by mixing cement with water, sand and aggregate.
What are the advantages and disadvantages of concrete?
Concrete is easily formed into different shapes before it sets hard. It is strong when squashed, but weak when bent or stretched. However, concrete can be made much stronger by reinforcing it with steel. Some people think that concrete buildings and bridges are unattractive.
What are the disadvantages of limestone, cement and mortar?
Limestone, cement and mortar slowly react with carbon dioxide dissolved in rainwater and wear away. This damages walls made from limestone, and leaves gaps between bricks in buildings. These gaps must be filled in or ‘pointed’. Pollution from burning fossil fuels makes the rain more acidic than it should be, and this acid rain makes these problems worse.
