Important Compounds of Transition Elements Video Lecture - NEET

hello friends this video on DNA block
elements part 30 is brought you by exam
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let's talk about some of the important
compounds of deep block element the
first is oxides and observe islands of
metals see oxides are form when you
react metal with oxygen high temperature
all metals except scandium see they form
oxides except SC scandium all this metal
form metal oxides right and all these
metal oxides are typically ionic we have
seen that most of the sir ionic and
highest oxidation states are shown by
these oxide why because this oxygen has
high electronegativity so this example
fe 2 o 3 oxygens in is + 3 MN 207
oxidation state is plus 7 so high
oxidation states are shown by these
opsite and also as oxidation number
increases for these oxides so oxidation
number of transition metal is directly
proportional to the ionic character for
its inversely proportional ionic current
right so oxidation number increase the
ionic character decrease the covalent
character increase and also the acid II
character increase okay
so oxidation number of transition
opposition number of oxidation state of
transition metal has directly reversed
from the covalent character and is
directly proportional to as adding
behavior we have seen higher oxidation
states acidic for example mn 2 O 7 is
oxidase a big M no.2 is space
wait these things we have seen as the
oxide we have seen not of actually oxide
for example B 2 O 5 is acetic oxide cro3
is acidic oxide MN 2
as the offside now these the oxidation
states are pretty high we talked about
basic oxides we have oxidation state
pretty low for example MN o f e o 8 plus
2 plus 2 or vo plus 2 these are anak ni
o also plus to talk about em protocol
oxide em photorec outside are they have
not very high not very low oxidation
number for example MNO 2 plus 4 vo 2
plus 4 right CU o plus 2 so these are
the ones which are empty
ok the next important compound is
potassium dichromate k2cr2o7 this
compound you must have used this
compound in your lab it is used in the
leather industry it is also used as
oxidant in the preparation of Mineo so
compounds it is prepared from chromate
in comment comes from chromite ores so
let's see the preparation of this will
take this chromite over f e CR 2 O 4
this is chromite ol this is chromite ore
from this what we do is we react with
any 2 Co 3 and oxygen write a balanced
equation what you get is na 2 cro4 and
Fe 2 O 3 and carbon dioxide this is what
you yeah okay and this is yellow yellow
that so once you get na to see out of 4
you filter this and you as to divide
this with sulfuric acid right so you add
h+ to it so what you get is na 2 CR 2 7
right this is called sodium dichromate
so once you have sodium dichromate and
also you get na plus ions and order
okay so once you have the sodium
dichromate after you react this sodium
dichromate with KCl see sodium
dichromate actually is more soluble in
KCl so what you get is potassium
chloride in the react you get k2cr2o7
and sodium chloride this is orange
crystal okay
this orange crystal of potassium
dichromate crystallized out and you get
this potassium dichromate okay please
note this chromate and dichromate SAR
inconvertible in the aqueous solution
depending on the pH of the solution for
example I have this CR - and make it
acidic it becomes cr2 o7 and what okay
same thing if I have CR 2 O 7 minus 2
this one you have this basic solution it
becomes CR o for 2 - n what these are
interconvertible okay so see our own 4-2
and CR 2 O 7 minus 2 these are
interconvertible you see CRO 4 minus 2
we had we added this H+ made as a big
envy what CR 2 O 7 minus 2 okay so we
talked about the structure of CRO 4
minus 2 this is the one this is this is
straight tri hedral and if you talk
about the structure of dichromate plus 1
CR 2 O 7 - 2 this is again 2 tetrahedral
they are two tetrahedral use this is the
structure this angle is 120 63 179
picometer is the bond length and this
angle chromium and oxygen this bond
length is 163 Pico meter okay so this
potassium dichromate actually is a very
very strong oxidizer
and this is actually used as a strong
oxidizing agent in the industry example
k2 or let me give the this one thumb cr2
o7 to - actually if you see you react
with acid and take this electron and it
becomes 2r c r3 plus and it gives some
water
so you see plus seven oxidation state
becomes plus three it get reduced and
thus it is a good oxidizing agent okay
the next important compound is 4d
blockers potassium permanganate kmno4
very important compound
this is prepared by a fusion of mno2
with alkali metal hydroxide and
oxidizing agent with kno3 so you see I
have mno2
with alkali metal hydroxide this
production right right for example
potassium hydroxide and oxygen you get 2
K 2 MN o 4 + 1 + 1 e 2 s and this is
actually done dream okay now this dark
green embryo for 2 - whatever you got
this is f li we see dogs in ml for 2 -
right this dark green actually when us
defy this you get em into 4 kmno4 can
you get a menu - right
and you get some water molecules so m
enough for 2 - this is available too -
actually when you justify it becomes a
metaphor - okay
this is paramagnet
okay so if you talk about the commercial
preparation of this what we do is we
take alkaline oxidative fusion of MN -
and that is being followed by
electrolyte oxidation of magnet ions
see you get mno2
you fuse this with Koh and oxidized by
air you get manganate ion mno4 - - this
is my Nana died on and this is
permanently on okay so once you get this
you do electrolytic oxidation and this
is done in alkaline solution alkaline
solution so what you get is what a
magnetized a metaphor - is permanent eye
on a metaphor - - is magnetized and
magnetite is green colored dark green
and permanganate ions dark blue in color
and if you see the structure of these
magnetized in permanganate ions both are
tetrahedron and actually can convert
this they also interconvertible for
example I take came in a for magnet ions
and I heat this you get k 2 MNO for a
bar magnet iron becomes Magneton and
mno2 and oxygen is the balanced reaction
so came and a for power magnet can
actually recover into magnet
okay so mno4 2 - this is green
tetrahedral paramagnetic paramagnetic
and this is dark purple tetrahedral this
source of mahogany the only difference
in the color okay
and this is actually uses good oxidizing
agent s divided kmno4 solution it can
oxidize
oxalates to carbon dioxide oxalate
it can be oxidized to carbon dioxide it
can oxidize Fe 2 plus 2 Fe 3 plus it can
oxidize I D - I - all these are done by
is d5 you must have seen this term
acidified Canada for very very strong
oxidizing it now i acidify see if you
talk about SD widest dividing spot h+
right so if you talk about mno4 minus
ion okay so this will take one electron
and it will become even afford to - I
have seen this
now this mno4 minus ion in presence of h
class it will take 3 electrons and
becomes a minute 2 + 2 h2o the same mno4
minus ion if you see in the presence of
more acid 8 h+ will take 5 electron and
become event 2 plus plus 4 h t see the
role of mno4 is oxidizing it right so in
this case it is getting reduced from
plus 7/2 plus 6 in this case from plus 7
plus 4 little bit of acid a more acidic
plus 7/2 plus - highly reduction if it
if it reduce from plus 7/2 plus 2 then
it will oxidize something more correct
so more acidic is the medium more is the
oxidizing power of came in the foil and
that's why we use the term acidified
came in a form without acidic medium
mno4 came in a for production permanent
is not that strong oxidizing is in but
in place of acid in helium it is a
strong oxidizing agent now we'll take
some reactions where s defied kmno4
actually i use this word now SC defying
because we have seen that in case of
acidic medium this reacts better I told
you
iodine it will oxidize that
you take em in a full - and we'll take
acidified medium so it will form
mn 2 plus water and i yes you can
actually balance this is 216 h+ and this
is 2 this is 8 and this is 5r same thing
iron also you have iron Fe 2 plus in the
presence of mno4 minus like an acidic
medium it'll oxidize it will get
reviewed itself and oxidize iron 2 2 + 2
island 3 plus and this guy is yellow in
color eyes and is a quick 2 + s green
color okay oxalate ions also it can
actually or is there oxidize see see you
OH - Ashley Epps from that see you - and
use again mno4 minus use am acidic
medium to make it petrol oxidizing agent
you get em in 2 plus and some water
molecule and this comes all this carbon
dioxide this is a reaction okay
similarly in fact hydrogen sulfide is
also oxidized again a mineral for - this
is more strong increase of acidic
mediums will add some acidic medium it
becomes MN 2 class and some water
molecule comes out and you have sulfur
mine okay Veck sulfide is also oxidized
to sulfate so 3 2 - when you have em in
- four - as oxidizing agent in presence
somes acidic medium you get em n 2 plus
plus some water molecule and you get so
4 2 - c b:c it oxidized so many things
even my tribe can be oxidized to nitrate
no.2 - in the presence of two mno4 minus
and some acidic medium you see that it
becomes mn 2 plus and n both 3 minus n
what so here also if you see all these
things are getting oxidized but this is
happening in the presence of sd5 came in
1/4 what if we have little alkaline or
neutral came in for HC de so now we have
alkaline or neutral its little common or
neutral so let's see
I would iodide iodine if you see I - was
being oxidized to i2 but here in case of
acidic medium we just saw but if it is
not a CD and let's see the reaction just
water a little medium so it becomes M
no.2 and it gives - H - and you get I go
3 - you talk about thiosulfate it is
oxidized to sulphate s - 3 2 - you have
react with 8 and 8 mno4 minus n some
water molecules right it becomes M in
row 2 and s 4 - - and watchman's same
thing with the magna salt
they are oxidized 2 MNO 2 so I have a 1
of 4 - with - salt and some water
molecule it will all get oxidized 2 MNO
2 and so this is the balanced reaction
does we see that key monopolist strong
oxidizing agent in case of acidic medium
talked about the uses of came in a 4 as
you discussed
oxidizing agent so it is use as oxidant
in organic chemistry most popular
oxidant in organic chemistry it is used
to bleach bleach wat bleach wool cotton
silk it is also used for deep
colorization of oil you want to
decolorize oil then this came in a
forest use there thank you visit exam
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