C1.2 Limestone and building materials Flashcards
What is limestone used as?
a building material
What happens when calcium carbonate is decomposed by heating?
calcium oxide and carbondioxide are made
What is the reaction called when limestone is heated to form calcium oxide and carbon dioxide?
Thermal decomposition
What other carbonates decompose on heating in a similar way to calcium carbonate?
carbonates of magnesium, copper, zinc and sodium
What is limestone mainly composed of?
the compound calcium carbonate
CaCO3
What is thermal decomposition?
When one substance chemically changes into at least 2 new substances when heated
Why may it be difficult to thermally decompose some carbonates ?
As a bunsen burner can’t reach high enough temperatures to thermally decompose some carbonates.
What is produced when calcium oxide reacts with water?
calcium hydroxide.
What can calcium hydroxide be used to do and why?
It can be used to neutralise acids as it is an alkali.
eg - neutralise acidic soil
What is limewater?
A solution of calcium hydroxide in water.
When calcium hydroxide reacts with carbondioxide , what is produced?
calcium carbonate
Describe the test for carbon dioxide
Limewater is used as a test for CO2. Carbon Dioxide turns limewater cloudy.
When carbonates react with acid, what is produced?
carbon dioxide, a salt and water
How is cement made?
limestone is heated with clay
how is mortar made?
limestone is heated with clay to make cement. Cement is mixed with sand.
How is concrete made?
limestone is heated with clay to make cement. Cement is mixed with sand and aggregate.
What are some negative impacts of quarrying limestone?
creates noise and dust
destroys habitats
Waste materials produce unsightly tips
What are some negative impacts of making things from limestone?
cement factories make a lot of dust- breathing difficulties
energy is needed to produce cement- using fossil fuels
What are some positive impacts of quarrying limestone?
limestone provides things people want- homes
limestone products use to neutralise soil
quarrying provides jobs
Why is limestone a good building material?
widely available
cheaper than granite or marble
quick and cheap to construct buildings with
does not rot like wood
fire resistant
does not corrode like some metals
What does calcium oxide react with to produce calcium hydroxide?
water
What does calcium hydroxide react with to produce calcium carbonate?
carbon dioxide
Why are buildings made from limestone affected by the products from burning fossil fuels containing sulfur?
Because sulfur reacts with oxygen to produce sulfur dioxide
sulfur dioxide causes acid rain that reacts with and erodes limestone
Calcium hydroxide + more water ————–
calcium hydroxide solution
calcium hydroxide solution + carbon dioxide ————
calcium carbonate
Calcium carbonate + heat ———-
calcium oxide
calcium oxide + water ———–
calcium hydroxide
suggest why concrete is stronger than mortar
as concrete contains aggregate
Name the type of reaction that takes place when calcium carbonate is heated strongly
thermal decomposition
When limestone was heated, suggest why the predicted amount of carbon dioxide was not obtained
- limestone was not pure- so less carbon dioxide was produced
- the temperature was not high enough so the limestone did not fully decompose
