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engineering HSC and IIT JEE main and
advanced videos Hello Friends in the last
lecture we have studied the new way
which was based on Farady's first law
but now we are going to do the numeriocal
 which is based on Faraday's
second row so let us see the question and
let us see how to find out the answer
so as mentioned on the screen there is a
question which is based on Faraday's
second law which says that it is not an
analysis 0.56 one gram of ZN that is
zinc is being deposited in a sense
containing a support solution so
calculate the mass of copper deposited
in another cell containing cuso4
solution and the both the cells are
connected in series as they have also
mentioned if you extra data that is very
much essential for us that is modular
weight of zinc which is given a sixty
five point four gram per moon and once
the weight of copper which is given as
sixty three point five gram per mole so
this is a new making this is based on
Faraday's second ohm and since they have
mentioned that the cell is connected in
series it is quite obvious that it is
based on fairness second law because
finding second loss has only a theory
where the both the cells of both the
half cells are connected in series and
the same amount of turn is applied
towards the whole cell and the way
deposited is dependent on the equivalent
weight of the particular substance that
is getting deposited on the particular
electrode so based on this let us
differentiate or let us extract the data
from the given question and let us see
how can we find out the answer so given
it is
their product weight that is mass of
zinc s 0.56 one gram and for that we
have to calculate the mass or the amount
of copper which is getting deposited in
the set off see you see us for is
present so this is what we have to get
me and the next thing that they have
provided to assist molar mass of zinc
which is given as sixty five point four
gram per mole when that of Mullah mass
of copper is given as sixty three point
five gram so these are the data that are
being given with the cushion so now what
we are going to do is we have to
calculate what will be the mass of the
copper in the that would have been
deposited in the second set so before
doing this let us calculate the number
of moles of the zinc as well as the
number of moles of the electron that has
been involved in the whole process so
for that the first formula that we are
going to do is we are going to calculate
what is the number of moles of a
particular substance so first of all the
first thing that we are going to do is
we have to going to find out the number
of moles of the substance in this case
we have to calculate the number of moles
of zinc because the weight of zinc is
already provided to us so therefore
since we know the number of moles
formula that is Eddy's what's to be
divided by monogrammed it right in this
case the weight that is actually the
mass of zinc which is provided to assist
0.56 one while the Bolliger weight is
given to be sixty five point four gram
per mode so the answer would be softer
evaluating this we'll get an interest
so this is a value that we will get by
the number of moles that we have
calculation and now this number of goals
will be very much influential in finding
out the number of moles of copper how
but for that we have to calculate what
is the mole ratio and what is the more
racial equity the second thing that we
have to do in this process is to
calculate the mole - mole ratio is
nothing but the amount of the substance
that is been getting deposited on the
number of moles of the substance that is
being deposited divided by the total
number of electron that take place in
that half cinema so let me tell you with
an example in this case the zinc is been
obtained when it is dipped in a solution
of ZN s o4 so in this case if i would
say that zinc with that is thing which
is present in an aqueous form that is Zn
2 plus will accept two electrons to form
zinc 19 only this will get deposited as
Z so therefore zinc 2 plus which is in
Equus form will accept two moles of
electron then only it will get deposited
as solid zinc so to understand food
issue let me give you the form of the
militias and since we are talking about
Z so therefore the mole ratio of zinc
will be equals to the number of poles or
the 1 mole of zinc divided by the total
number of moles of electrons involved in
that process so in this process so one
mole of zinc
[Applause]
we have to arrange or we have to this
solution has to accept two moles of
electrons so therefore the the mood
issue will be one mole of zinc divided
by the two moles of electrons required
in this process so similarly we could
calculate the mole ratio for coopera
why so how copper that is present in Cu
2 plus that is which is present in a
closed form it will accept two electrons
then only it will get deposited as
copper so therefore Cu 2 plus which is
in Equus from it will accept two
electron to form a solid copper that
will deposit only particular electrode
so therefore how can we calculate the
voltage shown it will be very much
simple so therefore the moderation will
be for copper in this case will be one
mole of copper divided by the total
number of electrons that are being
involved in this process
to convert an Equus form of copper to a
solid form of copper is two moles of
electrum so this is how we have
calculated the mole ratio of copper
accessmode ratio of sink so by making by
understanding this 2 liters that we have
recently we have calculated we can also
find out what would be the number of
moles of copper and what would be the
number of moles of zinc that they are
being involved in the overall reaction
so let us see so for that we have a
formula since we know for
Faraday's second law of electrolysis the
number of moles of zinc or the number of
moles of I would say as a divided by the
number of moles of B it will be
equivalent to or it will be equal to
mole ratio of a divided by the mole
ratio of B so it has consider the mole
ratio of a as the mole - of zinc and the
voltage of B as mole ratio of copper so
therefore we could write the following
in this way s the number of moles of
zinc here I define the number of moles
of copper which is equal to mole ratio
of zinc - the mole ratio of copper so in
this case I could write the number of
moles of zinc that has been we have been
calculated as that is eight point five
seven seven in to 10 raise to minus 3
divided by the number of moles of copper
I will write it in this way that is n of
C U which is equal to the number of
moles of zinc which is being calculated
it was nothing but 1 bowl of zinc
/ - wait notes similarly we could write
it for the mutations copper also like
one mole of copper nearby - electrode
and by this process this - later - later
on we'll get a lot and because of the
help of this we could calculate what
will be the number of copper so let us
so therefore the 8.57 7 into 10 raise to
minus 3 divided by the number of moles
of copper is equals to 1 mole of zinc
divided by 1 mole of O therefore the ncu
that is the number of moles of copper it
will be 8 point 5 7 7 into 10 raise to
minus 3 into 1 mole of copper they are
by one mole of zinc so this will cancel
out each other because it is the number
of moles so therefore the Enmore of Cu
will be so the number of moles of copper
must be calculated so now because of the
help of that we could calculate what
would be that amount on what could be
the mass of the copper that has been
deposited in the half same page so
therefore what I could write it as since
I know I provide the number of moles of
copper as the mass of copper that is
weight of copper the other ban moniker
weight of copper so the number of moles
of copper has been calculated as 8 point
5 7 7 into 10 raise to minus 3 and
therefore the mass of copper that has to
be calculated or the amount of then has
to be calculated divided by the
molecular weight of copper so in this
case the only bit of copper that they
have provided to us is 16 3 point 5 gram
per mole so therefore the mass of copper
will be 8 point 5 7 7 into 10 raise to
minus 3 into sixty three point five so
if you calculate this thing's we could
get you could get the answer is zero
point 5 4 4 gram so this is how we could
calculate the amount of a particular
substance involved in series of the
cells that are connected with each other
and that will follow Faraday's sec
so this wasn't even simple to calculate
so thank you friends for watching this
video I hope you have got an idea that
how to calculate this kind of data and
how to give it this kind of requirement
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