Page 34 - Curriculum Visions Dynamic Book

Copper sulphate
Copper sulphate occurs as a blue solution or crystals. It can be made by reacting sulphuric acid and copper carbonate.
Copper sulphate is widely used as
a fungicide. Originally it was probably used in a pure form as a seed covering
to protect the seed from rotting before
it could germinate. Later it was combined with lime to make Bordeaux mixture
(see page 42). It is also used to treat
wood and preserve it from attack by fungi, moulds and other rotting organisms.
A white form of copper sulphate (called anhydrous copper sulphate)
will absorb large amounts of water and can therefore be used as a drying agent. Anhydrous copper sulphate can also
be used as a simple test for the presence of water because it changes from white to blue when in contact with water.
Preparing copper sulphate
Dilute sulphuric acid and green copper carbonate produce a blue solution of copper sulphate.
 Sulphuric acid is added to copper carbonate powder to produce a solution of copper sulphate that can be evaporated, leaving copper sulphate crystals. A copper sulphate solution can also be produced by adding sulphuric acid to black copper oxide powder.
EQUATION: Reaction of sulphuric acid and copper carbonate
Sulphuric acid + copper carbonate ➪ copper sulphate + carbon dioxide + water
H2SO4(aq)
Sulphur
Oxygen
+
CuCO3(s)
+
Hydrogen
➪ CuSO4(aq) +
CO2(g) +
H2O(l)
Sulphuric acid
Copper carbonate
Copper sulphate
Carbon
◆
◆
➡
Copper
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