L13 : Displacement reaction - Metal & Non-Metal, Science, Class 8 Video Lecture

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nonmetals part 13 is brought to you by
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now that we are talking about reactivity
of various metals we are going to talk
about displacement reactions now these
reactions give better evidence about the
reactivity of metals because so far we
saw that some metals vigorously react
with what their some metals do not react
at all with water some metal reacts with
oxygen some doesn't react at all so the
there is a lot of variation in the
reactivity of metals to different
substances now these reactions give us a
better idea to decide which metal is
more reactive than the other middle so
it helps us to tell the reactivity of
various metals comparative or relative
to each other so basically we can see a
negative suppose you are given two
metals copper and iron so how do you
know whether copper and react is more
reactive than iron or Alan is more
reactive than copper so it is difficult
to answer such questions because copper
might react well with water
I don't might not react with water but
again on the other hand I think might
react with air copper might not react
with air so these kind of medicinal
pencils might be there so such reactions
so when we talk about displacement
reactions these reactions occur when a
metal is put in an atmosphere shell and
that ACMA solution is a compound of
another metal okay let me give you an
example
let us suppose you have a beaker inside
this beaker you have copper sulphate
solution it is an aqueous solution so
inside the beaker let us say you have
copper sulfate solution and you have put
an iron nail inside this solution so
basically you want to see the reaction
between iron and copper sulphate
solution so what you are doing
which is the matter here iron is a metal
and iron is put in an aqueous solution
and what is the aqueous solution it is a
compound of another metal what is that
another metal that is copper so
basically if you want to see out of iron
and copper who is more reactive
you can put one metal into a solution of
another metal so here we have put iron
in a solution of copper sulphate now how
this will help you to tell which metal
is more reactive we will see that as it
is later now it has been observed that
in this kind of situation for example
when an iron nail is put into a copper
sulphate solution over a period of time
it was seen that the solute color of the
solution changes normally coppers and
pure solution is blue in color but over
a period of time the blue color fades
away so why that happens due to the
reaction of iron with copper set bit
solution so over a period of time a new
thing is formed that is called atoms
healthy and you know the formation of
iron sulfate the blue color fades away
that means either reacts with copper
sulphate solution you do that reaction
only you are seeing change in Pelham
again if you take some other example let
us say again you have taken a beaker
with copper sulphate solution now
instead of iron now you have put zinc so
you have just put a small piece of zinc
or a small granule of zinc in copper
sulphate solution now in this case also
you see that after some time the color
changes so the color of zinc is like
white so the here also you see that the
blue color fades why it fits because
reaction happens and formation of zinc
sulfate happens due to the formation of
zinc sulfate the pallor of copper
sulphate solution fades here another
example can be taken where instead of
copper sulphate solution you take zinc
sulfate solution so here you have taken
zinc sulphate solution and in zinc
sulphate zone
you have taken a small piece of copper
so it is just the opposite of second
scenario so if this is second scenario
and this is third scenario second and
third are just the opposite thing
Yin was the middle solution was of
copper here this co solution is of zinc
and the metal is copper in this case it
is seen that there is no change in color
why there is no change in color
that means no reaction is taking place
that is why there is no change in color
if some reaction will take place that
means some new compound will be formed
so there will be some change in palette
but here there is no reaction take for
this not that it is surprising now when
the here reaction took place then why
there is no reaction taking place here
so that became a question and that is
what is answered by the concept of
displacement reaction so the concept is
very simple it says that a more reactive
metal with all these displays a less
reactive metal more reactive this whole
powerful so more powerful person always
replaces the less powerful person to
send everything here so in now you can
take the same example again so this was
your beaker number two and this was your
depend of a tree so in this beaker this
was your copper sulfate and in this
beaker it was your zinc sulfate in this
beaker it was your zinc and in this
beaker this was your copper now in this
case what happened the color change so
in this beaker color changed and is this
beaker no color change correct so that
means what is happening in this beaker
in this beaker reaction is taking place
that is why there is change in color so
what reaction is taking place let us try
to see to hear the reaction that was
taking place was zinc was combining with
copper sulfate to form zinc sulfate
plus copper now the color of copper
sulfate goes blue that is why earlier
the solution goes blue in color but the
color
of zinc's and failed is it zinc sulphate
is actually colorless so that due to the
formation of zinc sulfate gradually this
blue color of the solution starts to
fail so that means in this case what is
happening if you look at the reaction
very carefully zinc is actually
replacing copper from copper sulphate
solution so zinc is actually replaced
copper and taken the place of copper to
form zinc circuit that means zinc is
more reactive than copper so as per the
concept which I told you that more
reactive will displace the less reactive
so here more reactive should be zinc
because zinc has displaced copper so
this shows that zinc is more reactive
than copper now in this scenario what
happens here copper is reacting with
zinc sulphate now as I told you the
solution will change color
only if copper is able to displace zing
now what did we see we see that zinc is
more reactive
that means copper is less reactive than
zinc and a less reactive metal will not
be able to displace a more reactive
metal therefore copper will not be able
to displace zinc so if you look at this
experiment this clearly tells you that
zinc has a move thinking has more
reactivity than copper so the relative
reactivity between zinc and copper can
be easily determined with the help of a
displacement reaction right so this is
the concept of displacement we actually
it actually tells you which metal is
more reactive than the other metal so
the simple concept of displacement
reaction is that you have a metal EA you
have a metal B so when you combine metal
a with salt solution of metal B then you
what you get you need salt solution of
metal a and metal B when do you get this
only if metal a is more reactive than
metal B this this will hold
Morland as that case if method II is
less reactive than metal beam then there
will be no reaction at all so let us
look at an example for this so what will
happen if iron combines with copper
sulphate solution so here item is metal
a and copper is metal B so in this case
since iron is more reactive than copper
therefore iron will be able to displace
copper to form iron sulfate let's pop it
so this shows that iron is more reactive
than copper so this is how this
placement reactions work so based on
whatever we have discussed so far on
physical and chemical properties of
metals and nonmetals we can quickly have
a comparison between metals and
nonmetals so metals are nastiest
nonmetals low luster
there is no shine on nonmetals the only
exceptions Ione methods are solders they
produce linking sound nonmetals lowering
in some metals are good conductors of
heat and electricity nonmetals and to
will conductors so like you can see the
conducting wires they are all metals
metals are malleable ductile but
nonmetals are not so nonmetals dell'utri
if you try to beat them they break into
pieces metals have high density
nonmetals have low density metal oxides
are blazing through oxides of metal for
example by meshing of oxide or iron
oxide they are all basic in nature but
nonmetals their oxides are acidic like
carbon dioxide sulfur dioxide they all
combine with water to form sulfuric acid
carbonic acid etc metals react with
water they react with acids nonmetals do
not react with any of them metals react
with bases to release hydrogen but non
metals react nonmetals directly do not
react with bases but their oxides
a quick basis to release water so these
are some of the distinction between
metals and nonmetals properties thank
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