Summary questions – Building materials from rocks
1
2
a) An element contains only one type of atom.
true/false
b) Silver oxide is an element.
true/false
c) Calcium carbonate CaCO3 contains three elements.
true/false
d) The formula of calcium carbonate contains six atoms.
true/false
e) Sand and water is a mixture.
true/false
f)
true/false
Sand and water are hard to separate.
g) Decomposition means the same as synthesis.
true/false
h) CO2 contains two elements and three atoms.
true/false
The two elements present in all carbonates are _______________ and _______________.
Magnesium carbonate has the formula, ____________. It is a compound because it
contains more than one type of _______________ bonded _______________. When it is
heated, it _____________ to give magnesium ______________ and carbon
_____________________ gas. This type of reaction is called _____________________
decomposition.
The gas can be tested for using _________________________ which goes
______________ if the gas is present.
3
Limestone is calcium carbonate/calcium sulphate and has the chemical formula
CaCO3/CaSO4 . It is a very rare/abundant chemical and has many uses.
When it is heated in a lime kiln/blast furnace it decomposes to give solid calcium
sulfide/calcium oxide and the gas carbon dioxide. This reaction is an example of
catalytic/thermal decomposition. One of the uses of limestone is as a building material.
Also, when it is heated with sand/clay it gives cement and when it is heated with a mixture
of sand/cement and sodium carbonate/sodium acetate it gives glass.
4
Quicklime has the chemical name calcium ______________ and is formed when
limestone (chemical name ____________ __________) is heated strongly. When
water is added to quicklime, an ________________ reaction occurs which gives out
a lot of heat energy. This reaction can be used in kits to ____________ up food or as
a hand warmer. The substance formed in the reaction between quicklime and water
is called ___________ ____________ and has the chemical name ___________
______________ (chemical formula = Ca(OH)2). This chemical is used in the
__________ trade where it is mixed with sand and water to form ___________
mortar.
When a lot of water is added to _______________ _________________, lime water
is formed and this reacts with carbon ___________ gas to give calcium
_____________ and water. The calcium ____________ is a solid and turns the lime
water ________, because we get back to calcium ______________ which is what we
started off with. This series of reactions is called the ____________ cycle.