Formation of Complex Compounds and Catalytic Properties Video Lecture -

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let's talk about the complex science in
complex compounds are actually form when
the metal ions typically in this case my
transition metals they binds with
numbers of anions or neutral molecules
right and they bind to form complex
species and this complex species has
some characteristics this one if you see
is hexa aqua copper one copper with six
water molecules okay another example of
complex ions can be fe CN 6 3 months or
fe CN 6 4 - or see you in it's 3 for 2
plus so here this NH 3 CN - these are
all ligands okay and these transition
metals actually form large number of
complex of all why the reason is why
large number come one the first reason
is sites size is small for the
transition metal size is small next is
the ionic charge is high ionic charge is
high for transition vector okay
and third is the D orbital electrons the
orbital electrons are there so we have
SN D orbitals electron more electrons
for bonding
okay and these D orbitals electron
actually accept the lower and lone pair
of other group so very even if it has
vacant d-orbital it is useful even if it
has some electron it is useful I need to
accept the electrons donated by at the
crew okay
and this ions with such characteristics
having strong tendency to attract with
ligands such as water ammonia CN - all
of which have highly electronegative
atom
and she reads it okay see what I'm
saying is these I this is metal ions
example metal ions these metal ions have
tendency to interact with these ligands
ligands for example my ammonia CN minus
water molecules these ions have tendency
to drag a form born with this ligands
okay and these ligands actually have
highly electronegative either example if
see nitrogen oxygen these are all highly
electronegative atom and these have
unshared electron pairs also if you find
actually draw the shape you will see
that they have unshared electron pairs
okay these metals with positive charge
or metal ions interact with ligands
these ligands are ammonia CN minus water
molecule and these ligands have highly
electronegative atom and unpaired
electron and these bind together and
they form complex times okay now the
next important part of the deep rock
element is the catalytic properties see
whatever catalyst catalyst are nothing
but any substance which accelerates the
rate of reaction example this is a
biological catalyst this catalyst the
green one is my catalyst this catalyst
provides a site where the reaction can
happen it forms an intermediate complex
and with this the product is is the form
this is was my reactant and you get
product using this catalyst because this
catalyst is not being used but it helps
in providing the space surface where the
reaction can happen also sometimes I
intermediate complex this form it's easy
to break okay
now the transition metals I am saying
they have catalytic property why see
there's several reason the first is the
transition metals have ability to adapt
to variable oxidation state this
variable oxidation state is one of the
key reason we'll discuss these in
details now okay second one
it forms complex you just see and these
complex
you can also forms unstable intermediate
complex the way we have seen the sun's
unstable in to make complex it forms the
third is it has partially be filled
orbital partially filled D orbital and
this D orbital actually this provides
active site this provides active site
and also the large surface area for
adsorption or I will say ends option at
the option of what it's option of
reacting molecules and that's why if you
see the in hydrogenation we use platinum
but we make sure this platinum is very
mine you too I mean when the crust its
crust so that all spotted so that you
have more surface area you have anything
you crush it you make it partner the
effectively you end up increasing the
surface area right so this has this
property because of these three
properties actually these D block
elements have catalytic property okay
let's see the examples of this for
example the first one the variable
oxidation oxidation state if you see Fe
three-plus these has capability of
converting into Fe 2 plus easily and
this catalyze the reaction between
iodine iodine and persulphate will show
you example you take Fe three-plus
you react with hi medicine what you get
is this the iron is reduced variable
oxidation see and this videos iron
Ashley D act with persulphate and gives
back Fe three-plus and you get a so for
donors so now you see you started with a
3 plus you get back a 50 plus thus Fe 3
plus is nothing but a catalyst but
because Fe 3 plus
actually change its oxidation state
easily it acted as a catalyst if you
talk about these two complex unstable
intermediate and gives active site so a
good example is iron iron is actually
finely divided iron is used as catalyst
for manufacturing ammonia or ammonium
god production in Haber process in Haber
process we use finely divided idly ie
divided by finely divided because if you
finally divide any metal you increase
the surface area we want more and more
surface area where reactant can be a job
and the reaction can take place another
again the nickel Potter nickel this is
also in powder form is used as a
catalyst in hydrogenation of unsaturated
hydrocarbon we have seen that platinum
platinum again the finely divided
platinum is used as catalyst to
manufacture nitric acid by three BIOS to
our process this o small process we
produce nitric acid and that we use
platinum as catalyst so for example v2o5
an ATM pentoxide this is also used to
manufacture South Korea said where when
we're in a pen talk side is my chemist
okay so as I told that these provides
surface area these catalyze because
these catalysts now has the D orbital
and s orbital so these DN s orbital
electrons Ashley it helps in binding the
reactant to this surface area and with
this the concentration of reactant the
surface area increase in the
concentration is increased norm at some
locate the local I mean some local place
Sam
my catalyst at this if I increase the
concentration of reactant why because
reactant forms bond with this D orbital
since the reaction of the concentration
of the reactant has increased in this
area the reaction is faster okay so
that's the role of catalyst this was the
picture for the hydrogenation if you see
this is hydrogen is a nickel catalyst
this is the nickel catalyst and hydrogen
bonds are broken and this Michael
provides a surface area where this
reaction can take place and
hydrogenation take place so if you want
more details on hydration you can watch
my videos where we have discussed the
process of hydrogenation in more
detailed way now but doc thank you visit
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