What do you understand by reativity of metal . Explain your answer with three points.
Answers
Metals react with oxygen to form metal oxides.
Metals + Oxygen -----> Metal Oxides.
The reactivity series of metals are:
Potassium
Sodium
Calcium ----->Highly reactive metals
Magnesium
Aluminium
Zinc
Iron -------> Moderately reactive metals
Lead
Copper
Mercury --------->Less Reactive metals
Silver
Gold
Metals take place in chemical reaction according to their reactivity.
The reaction of different metals with oxygen to their reactivity are:
(a) Sodium and Potassium combine with oxygen to form their oxiden. The reaction is so vigorous that it catches fire.
(b)Magnesium when heated burns with a bright light.
(c)Aluminium develops a thin oxide layer.This thin layer protects the inner layer from further corrosion.
(d)Copper,when exposed for long time form a dull green coating.It is a slow reaction.
(e)Iron exposed for long time in moisture forms Iron oxide.This is called rust.This process is called rusting.
(f)Gold do not react with oxygen.
The reaction of metals with water is
(Metals + Water --------> Metal hydroxide + Hydrogen.All metal hydroxides are basic in nature.)
Magnesium do not react with water.It reacts with hot water to produce Magnesium Hydroxide.
Aluminium,Zinc and Iron do not react with cold or hot water.They only react with steam.
Lead,Copper,Silver and Gold have no reaction with cold and hot water.
Metals react with Hydrochloric acid to form Chlorides + Hydrogen.Metals + Acids ------------>Salt + Hydrogen
Metals react with bases : Metals + Bases -----> Salt + Hydrogen
Displacement Reaction:The reaction in which more reactive metal flows its salt solution.
eg:-Zinc can displace Copper from Copper Sulphate Solution.