Question

explain reactivity series with example.

Answer 1

in reactivity series Metals are arranged according to their reactivity...Pottasium is at the top of the series which means pottasium is highly reactive metal...

Pottasium is highly reactive because when expose to air it starts reacting and catches fire...

The Following metals come under the reactivity series :
Pottasium
Sodium
Magnesium
Aluminium
Zinc
Iron
Tin
Lead
Hydrogen - { not a Metal }
Copper
Mercury
Silver
Gold

As we go fown the series , Metal reactivity decreases so Gold is the metal which is least reactive or we can say it is Inert..which do not react easily...

This series help to determine whether a Matal displace the Metal from its MetalSulphate Solution...

Note that A highly reactive metal will displace the metal from the Metal sulphate solution only if Metal in the Metal sulphate solution is least reactive....else No reaction will take place..

For Example :

If You Dip an iron nail(Fe) in Copper sulphate solution( CuS04) which is Blue in colour...Displacement reaction takes place as iron being highly reactive than copper so it displaces Copper from its Solution which results two observations

1-> copper gets deposited on iron nail so colour of the nail chages to Brown...as Copper is brownish in Colour..

2->The Copper sulphate soluion Blue colour changes to Green which is nothing just an iron Sulphate solution..

Reaction :

Fe ( Iron nail ) + CuS04 -> Fe2S04 + Cu ( Copper )

Lets take another Example :

If we take Zinc Sulphate Solution and Dip Copper nail into the Solution...No reaction takes place as Copper is less reactive metal than Zinc ( See reactivity series)..so it fails to displace the zinc from its Solution...

Reaction : ZnS04 + Cu - > No Reaction

One more thing about Metal reactivity is that Metal which looses its electron easiliy from its Valence shell considered as highly reactive Metal...Pottasium looses its electron easily as comparef to other metals so it is highly reactive metal...Gold is least reactive metal as it doesnt loose its elecron easily...You can observe that Gold cannot corrode easily when expose to air but other metal start reacting with air to form metal oxides....