Page 210 - Chemistry ICSE Class X

196 ICSE Chemistry – 10
ƒ Due to its low density and high tensile strength, aluminium is used
in construction industry.
ƒ Aluminium form highly useful alloys. Alloys, such as duralium and
magnalium, are used for making bodies and other parts of aeroplane,
cars, buses, furniture, etc.
ƒ Aluminium powder is used in making paints and explosives and as a
reducing agent in metallurgy.
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Corrosion (or Rusting) of Iron

What is corrosion
Most of the commonly used metals are strong, ductile and malleable. When
in use, these get exposed to the reactive environment. Many of them lose
their shine and get covered with a coloured layer on them. Some even lose
their strength and become brittle and weak. This happens due to chemical
reactions of the metals with the environment. In common language, this
phenomenon is called corrosion.
Slow destruction of metals due to their interaction with the
environment is called corrosion.
Corrosion takes place on the exposed surface. When the upper layer
of the metal gets corroded, then the inner surface of the metal gets exposed,
and the corrosion then continues up to certain depth.
Corrosion Corrosion of iron is called rusting.

What are the necessary conditions for the corrosion of
iron (rusting) to take place
To know of the conditions necessary for the corrosion of iron (or rusting)
to take place, perform the following activity:

ACTIVITY 1 Aim: dŽ ĮŶĚ ĐŽŶĚŝƟŽŶƐ ŶĞĐĞƐƐĂƌLJ ĨŽƌ ĐŽƌƌŽƐŝŽŶ ŽĨ ŝƌŽŶ ;Žƌ ƌƵƐƟŶŐͿ ƚŽ ƚĂŬĞ ƉůĂĐĞ
Materials required: ŽŝůŝŶŐ ƚƵďĞƐ͕ ŶĂŝůƐ͕ ĐŽƩŽŶ͕ ĚŝƐƟůůĞĚ ǁĂƚĞƌ
Procedure: dĂŬĞ ƚŚƌĞĞ ĐůĞĂŶ ĂŶĚ ĚƌLJ ďŽŝůŝŶŐ ƚƵďĞƐ͘ >ĂďĞů ƚŚĞŵ ĂƐ ͕ ĂŶĚ ͘

ƒ /Ŷ ƚƵďĞ ͕ ƉůĂĐĞ Ă ĨĞǁ ůƵŵƉƐ ŽĨ ĂŶŚLJĚƌŽƵƐ ĐĂůĐŝƵŵ ĐŚůŽƌŝĚĞ ĂŶĚ
ĐŽǀĞƌ ŝƚ ǁŝƚŚ ĐŽƩŽŶ͘ WůĂĐĞ Ă ĐůĞĂŶ ŝƌŽŶ ŶĂŝů ŽǀĞƌ ƚŚĞ ĐŽƩŽŶ ĂŶĚ ĐůŽƐĞ
ƚŚĞ ŵŽƵƚŚ ŽĨ ƚŚĞ ƚƵďĞ ǁŝƚŚ Ă ĐŽƌŬ͘
ƒ WůĂĐĞ Ă ĐůĞĂŶ ŶĂŝů ŝŶ ƚƵďĞ ĂŶĚ Įůů ŝƚ ǁŝƚŚ ďŽŝůĞĚ ĚŝƐƟůůĞĚ ǁĂƚĞƌ͘
ŝƐƟůůĞĚ ǁĂƚĞƌ ŝƐ ďŽŝůĞĚ ƚŽ ƌĞŵŽǀĞ ƚŚĞ ĚŝƐƐŽůǀĞĚ ŽdžLJŐĞŶ ĨƌŽŵ ŝƚ͘
ŽǀĞƌ ƚŚĞ ǁĂƚĞƌ ƐƵƌĨĂĐĞ ǁŝƚŚ ŵŽůƚĞŶ ǁĂdž ĂŶĚ ĐůŽƐĞ ƚŚĞ ŵŽƵƚŚ ŽĨ
ƚŚĞ ƚĞƐƚ ƚƵďĞ ǁŝƚŚ Ă ĐŽƌŬ͘
ƒ WůĂĐĞ Ă ĐůĞĂŶ ŝƌŽŶ ŶĂŝů ŝŶ ƚƵďĞ ĂŶĚ ĐŽǀĞƌ ŝƚ ƉĂƌƟĂůůLJ ǁŝƚŚ ƚĂƉ ǁĂƚĞƌ͘
KďƐĞƌǀĂƟŽŶ͗ džĂŵŝŶĞ ƚŚĞ ŶĂŝůƐ ĂŌĞƌ ϯͲϰ ĚĂLJƐ͘ tŚĂƚ ĚŽ LJŽƵ ŽďƐĞƌǀĞ͍ zŽƵ ǁŝůů ĮŶĚ ƚŚĂƚ ŽŶůLJ ƚŚĞ ŶĂŝů ŝŶ ƚŚĞ ƚƵďĞ ŐĞƚƐ
ƌƵƐƚĞĚ͘
Conclusion: dƵďĞ ĐŽŶƚĂŝŶƐ ŽŶůLJ ĚƌLJ Ăŝƌ͘ dƵďĞ ĐŽŶƚĂŝŶƐ ǁĂƚĞƌ ďƵƚ ŶŽ Ăŝƌ ;ŽdžLJŐĞŶͿ͘ dƵďĞ ĐŽŶƚĂŝŶƐ ďŽƚŚ ŵŽŝƐƚƵƌĞ ;ǁĂƚĞƌͿ
ĂŶĚ Ăŝƌ͘ KŶůLJ ŝŶ ƚƵďĞ ͕ ƚŚĞ ŶĂŝů ŐĞƚƐ ƌƵƐƚĞĚ͘
Conclusion: dŚŝƐ ƐŚŽǁƐ ƚŚĂƚ ĨŽƌ ƚŚĞ ĐŽƌƌŽƐŝŽŶ ŽĨ ŝƌŽŶ ;Žƌ ƌƵƐƟŶŐͿ ƚŽ ƚĂŬĞ ƉůĂĐĞ͕ ďŽƚŚ Ăŝƌ ;ŽdžLJŐĞŶͿ ĂŶĚ ŵŽŝƐƚƵƌĞ ;ǁĂƚĞƌͿ
are necessary.