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advanced videos Hello Friends in the last lecture
we have shown a numerical which
was based on Farady's Law and now
we are going to solve another problem
which is based on Farady'sFirst Law  so
let us see and evaluate what is the
given requirement
Solutions say that how long it will take
to produce 2.41 5 gram of Ag that is
silver metal so in this case they have
been asking what will be the time
required to give 2.4 one gram of the
silver metal from its salt solution my
passage of 3 ampere of current and one
more additional portion that they have
been asked that is how many moles of
electrons are required and the molar
mass of the AG which is given as 107.9
gram per mole so the first thing that we
have to do is we have to extract the
data from the given cushion so the first
thing that they have given to us is 2.41
gram of AG which means they have
provided us the weight of the particular
substance that is been deposited which
is therefore W which is given as two
point four one five gram the next thing
that they have provided us s correct
that is I is equals to 3 ampere and the
next thing that they have provided us is
molecular weight of a gene which is
given as 107.9 gram per move and with
the help of this we have to calculate
what will be the time that would require
to give 2.41 5 gram of current been 3 a
pair of 2.4 and gram of the substance
when three a pair of 3 days pass through
the solution so for that we have a
formula that is W is equals to Z into I
into T divided by 9 6 5 0 0 coulombs so
the weight that has been already
mentioned the I is given the T is the
thing that we have to find out and 9 6 5
0 is already present in the formula so
before getting all those data but we
don't have the value of Z so how can we
can
you have said it is very simple as we
did in earlier Diego also said that is
equal to it it's nothing but molecular
weight divided by its valency of the
particular metal when it is present in
ionic form so in this case the molecule
bit of Ag is given as 107.9 divided by
the valency of or the oxidation of the
symbol is usually one
so therefore the valency is said to be 1
and the value of z is nothing but is
equals to the molecular weight itself
that is 107.9 so this is what we have
got the value of Z and now with the help
of this we are going to calculate what
will be the value of the time so now the
thing that we have to do is we have to
substitute the value of each and every
data that we have got right now so
therefore the weight which was given as
2 point 4 1 5 which is equals to Z that
we have bought as 107.9 into the current
that has been provided to us is 3 and P
R and the time that they have been asked
divided by 96500 Coulomb so therefore
the time can be written as 2 point 4 1 5
into 9 6 5 0 0 / 107.9 into 3 so now let
us calculate this thing and let's see
what we have 1 so we have got a value of
seven one nine point nine but this will
be in seconds because every unit that we
have taken right now is in gram or it is
an CGS unit so therefore the time will
also will have a unit in case of seconds
so therefore this will be the time will
be present in seconds
so we see the first answer we have
bought that is it requires seven one
nine thirty seven hundred nineteen point
nine seconds to give us a weight of two
point four one five gram of the silver
and three ampere of current is being
passed through the electrolytic cinema
but this is the first requirement that
we have estimated where the second
requirement is to calculate the number
of moles of electron so to calculate the
to calculate the number of moles of
electron we have a formula that is very
much relevant to us which says that as
we did a chapter
surjyada gate properties we know that
how to calculate the molecular weight so
we know that the number of poles can be
written as weight divided by the
molecular weight so in this case the
weight of silver is been provided to us
and the body weight of silver is also
provided to us and in the help of this
thing we could calculate that what would
be the number of moles of the silver
that is present in that measurement or
that much weight of that symbol and with
the help of this we could estimate that
what would be the number of moles of
electrons that has been participated in
this reaction so so the number of moles
which is denoted by N is nothing but
weight of silver divided by molecular
weight of Sigma which they have provided
assess the weight of zippor was given as
two point four one five grand on that of
molecular weight of silver or molar mass
of silver was been given as 107.9 so in
the help of this I could calculate what
would be the number of moles of silver
so let's see
so the number of moles of silver that is
present in this solution or in this
amount of weight or silver is zero point
zero zero two and we have to calculate
the number of moles of electrons so
therefore if this is the number of moles
of silver and the number of moles of
electron or the number of electrons that
have been deposited or that are being
oxidized by a single silver atom is one
so therefore if one single atom of a G
is donating or is been losing one
electron then this much amount of a G in
present in terms of the number of moles
will give the electron s therefore the
number of moles of electron will be zero
point zero two two into one mol of
electron which consists of messini 96500
Coulomb now will have a value of
- one two three so this is the number of
moles of electron that would be
participating in this whole reaction or
in this electrolytic cell so this is the
answer that we have got so thank you
friends so thank you friends for
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Kika - I thank you so much
