Chemistry - Limestone Flashcards
How does the stability of metal carbonates change as you go up the series?
The higher up the series a metal is, the more reactive the metal is and so the more stable the metal carbonate is. A stable metal requires a high temperature to decompose.
How can you measure the stability of metal carbonates?
The stability of the metal carbonates can be measured by heating the carbonate and bubbling the carbon dioxide given off through limewater. The quicker the limewater becomes milky, the greater the rate of decomposition of the carbonate (meaning the carbonate is less stable).
How is calcium oxide formed? What is it used for?
When limestone is heated strongly, the calcium carbonate it contains absorbs heat (endothermic) and decomposes to form calcium oxide. This is indicated by an orange glow as the limestone is heated.
Calcium oxide is a key ingredient in the making of cement and is also used to make certain types of plaster.
How is calcium hydroxide formed? What is it used for?
Calcium oxide reacts with a few drops of water to form calcium hydroxide, which is an alkali. This is an exothermic reaction, indicated by the water turning to steam. The solid remains white but crumbles into a powder as the water is added.
Calcium hydroxide is used to neutralise excess acidity, for example, in lakes and soils affected by acid rain.
How is limewater (calcium hydroxide solution) formed? What is it used for?
Calcium hydroxide dissolves in excess water to produce calcium hydroxide solution (limewater), which is used to test for carbon dioxide.
How can you test for carbon dioxide using limewater?
The carbon dioxide reacts with the calcium hydroxide (limewater) to form white calcium carbonate, which is insoluble and so turns the limewater ‘milky’.
How can you test for carbon dioxide using limewater?
The carbon dioxide reacts with the calcium hydroxide (limewater) to form white calcium carbonate, which is insoluble and so turns the limewater ‘milky’.
What are the many uses of limestone?
-Building material.
-Production of cement by heating powdered limestone with clay.
-Major ingredient in toothpaste.
-Food additive to provide calcium ions for strong teeth and bones.
-It can be processed as a useful raw material in the chemical industry.
-It can be used to neutralise acidic soil to allow plants to grow more effectively.
What are the advantages of quarrying?
-Vital building material
-Provides employment
-Supports the local economy
-Better local road system
What are the disadvantages of quarrying?
-Destruction of the landscape, as well as the wildlife habitats within the landscape
-Regular blasting produces excessive noise and dust
-Dust and extra vehicle pollution can lead to increased numbers of respiratory conditions, eg asthma
-Increase in traffic, eg transport lorries
