Alcohol Chemical Properties (Part - 14) - Alcohol, Phenol & Ether, Chemistry, Class 12 Video Lecture

hello friends this video on alcohol
phenyl ether part 14 is brought to you
by exam clear calm no more fear from
exam the next frame of reaction is the
reaction where the my CEO bond is broken
so here I have our it suppose to be h2o
H kind of thing so here this bond is
breaking see you wanted pro will see
different kinds of reaction the first is
with hydrogen halide is HX so I am ro
which is my alcohol reacts with HX this
bond breaks you get our X plus h2o there
is a Lucas test actually very very
famous test this is used to
differentiate between primary secondary
and tertiary alcohol the Derby tea which
you get is pretty fast intermediate
immediate this is 3d real qahal if it is
a after two three minutes it is to
degree and if there is no reaction we
say that it is 1 degree alcohol will
talk about the liquids test this is you
can test for turbidity actually right so
there we use alcohol plus HCl it gives
intense en to alcohol plus s unit gives
you in the presence of Jenin C into
Ashley you get turbidity that is our CL
this time when you get the stability
designs whether it is first degree 2
degree or 3 it is immediate it is 3
degree it takes to 3 minutes 2 degree it
doesn't happen this model here carbo
cation is form
and it can be either sn1 or sn2 reaction
sn1 or sn2 depending on this two degree
or one degree or three degree right it
is sn1 sn2 discovered ion formation is
there correct so if you want I can write
the mechanism for this so let's see this
is ROH this is it's plus X minus like HX
this is a pretty fast thing my H+ will
attack this oxygen lone pair or better
like this this oxygen lone pair red
package because this has electrons right
it's reversible at me and fast also so
what you get is ROH to transfer X - take
this protonation is done because which
is not that great living room but h2o
plus is a good living room
so now I have ROH two plus so it is a
slow process now you get AR + NH 2 now
you got our plus it's a simple reaction
so R + na will react with X - certainly
be our X Alex correct so it is
nucleophilic substitution reaction and
if we talk about the hydrogen halide
reactivity we have discussed this for
many times H is best in hbr and HCL in
that way in the nature rarely used and
if you talk about alcohol reactivity 3
degree is passed to degree in than 1
degree and that's why this reaction is
used for in Lucas test they toured this
Lucas test where do you want to find
whether the alcoholist pause degree 2
degree or 3 degree right so it is 3
degree it is immediate turbid it
to degree it is to five minutes you get
turbidity three degree there is no
reaction right this is my Lucas test and
this has nothing but same thing Co bond
is keyed so I have ROH react with a CL
in the presence of engine and CL 2 you
get up CL and this is 30 so let's see
the alcohol reaction be x3 there is
phosphorus try flying try it like so
here what we do is we have this alcohol
we react with px 3 you get our X NS 3 P
O so for bromo alkanes cycloalkanes
alright or Romana cane and cyclo alkane
we react either with PCL 3 pz l phi pbr3
example I have c2h5oh and react with PCL
5 I get C 2 H 5 CL + p OC + 3 + HC but
for IO double cane are I we react with
red phosphorus and iodine for example i
have c 3o h + iodine we use red
phosphorus i get 3 h 3i plus h 3 p o3
why I don't use H I hear because example
I have ch3oh if I use H I this essay
will reduce ch3oh to CH 4
that's why I don't you I think you've
discussed about these things the
haloalkane chapter
so I won't discuss much here
you discussed this actually so let's
move ahead with thin oil chloride soaked
in oil flow is nothing but s o c and so
here if example I have ROH you react
with associate to Co bond in even break
here you get our CL plus sulphur gas and
HCl and you have this in the mild basic
condition because I am i piloting it can
be is a catalyst so alcohol reacts with
non fluoride in the presence of mile
bees may be piloting to form hello
all teams and there's a good method why
why it's a good method because so2 is a
gas it emits right as seen is a gas
motor gas it goes off the system but
please know and they're poisonous so K
has to be taken right what you get is
output is exactly our CL only there is
nothing else so you do not have to do
any filtration to get I think it RC F
because these two are gases and they
goes or the system on its own but
they're poisonous so you have to take
care of this right
so see the reaction mechanism on this so
let's see ch3 ch2 watch okay let's see
this reaction mechanism so I have socl2
so this is how I have this guy socl2
correct oxygen slightly negatively
negative charge slightly positive shot
since the slightly poorer oxygen has
lone pair to give electron to this guy
right so what it will form is
a ch3 ch2 Oh since oxygen has given
electrons get a positive charge s and
then I have CL CL CL CL and I have Oh -
here right one more here I hand Oh mines
correct
now this OH - will keep the screen out
so this will go in this direction go in
this fashion the chlorine EV out what
you get is ch3 ch2 o+ still will be
there I think you had to be there Oh + s
4 CL yeah this is what you get the
chlorines out now what will happen is
this is a positive charge on this this
so2 will count this positive charge on
this oxygen so he missed a chair this
was a chair right he'll also use an H
correct also there is a CL - in the
system which we have got from here now
this oxygen will have a positive charge
be blown light so hydrogen will come out
and let's say I'll take care of the
positive charge right as plus will come
addresses we have seen so with this what
you get is ch3 ch2 and this so2 gas will
also come on and this chlorine will join
this guy in plus so2 and this h + NC
will combine to form HC and this is what
you will see how it works in SEO - now
it's double bond here right so this
chlorine will come on as CL minus will
be the positive charge this will come
out as - very negative charge and then
follow on so you get this combo
let's see the dehydration reaction one
thing you have seen this reaction so
anytime dehydration reaction so when you
treat the alcohol with protti acid like
h2s fo or h3po4 and give some heat the
water molecule is lost example I have
this come from
h NH here also if you see co bond will
break and this you get h+ and some heat
you get alkene then water comes out this
the dehydration reaction you want to see
the mechanism I'll show you h+ oxygen
has this lone pair it attacked with this
plus what happens here is next is carbon
has h to the positive charge on oxygen
viable oxygen has given electrons so
right oxygen gets a negative charge
positive charge this is fast
now OS 2 has to leave right OS to leaves
and this gets a positive charge this is
slow now since this carbon has called
positive charge it how to stabilize this
hydrogen C is okay Ali so this hydrogen
says I'll leave it should be the
negative charge here negative and
possible form 1 + H+ comes out correct
this is the reaction - and also observe
that 3 tertiary alcohol that is 3°
alcohol goes hydration goes hydration
easily since why because here carbo
cation has formed right 2 3 degree will
form of it and easily so for example if
you see I have c2h5oh you need h2so4 and
need a high temperature of 445
to make it two hulking same thing if you
have increase the reviews one degree
right
you may need to degree here say ch3cho H
yes this is 2 degree so here you need
only 85% of solution h3po4 and also you
need less than pressure maybe for 40
Kelvin and with this you get alkene if
you have tertiary alcohol pipe is all
the more simple for you example you have
something like this I think you need
only 20% as 3-view for you will live
even less temperature may be 355 Kelvin
and you get something like this correct
so dehydration is easy or three degree
now we talk about oxidation before we
talk about oxidation let's say some of
the common oxidants we have in the body
so let me write it for you guys actually
so if you talk about the strong oxidants
we have hno3 this is one chromic acid
h20 for chromates all cro4 - dichromate
salt cr2 o7 - - / magnet a metaphor -
maybe getting potassium permanganate
then I have Pyrrha dine die Pyrrha dine
chlorochromate rattling PCC and then I
have paradigm dichromate PDC right there
are so many exciting agents these are
all my strong and these are my weak
correct the Oregon oxy means in the
market machine use the typical oxidation
reaction will be something like this
I'll show you I have CH 3 CH which H we
do oxidation of this what you get is CH
3 Co th if I further do oxidation of
this I get CH 3 Co H okay this is the
typical reaction here if you see we have
breaking CH n o H bond this bond we are
breaking so CH and O is one we are
breaking and we are forming Co you see
that's what we are doing actually
correct it all depends on how strong
oxidizing agent it is correct and it is
also called d hydrogenation reaction
example I show you this reaction now
right if you add an oxidizing agent here
so this bond breaks this bond breaks and
what you get is our C you are see if we
see what we are doing is we are removing
hydrogen right to hydrogen so it is also
called dehydrogenation reaction but
actually the Sox in which we are
providing right actually if you see the
reaction is like this
h2o these two hydrogen's and this oxygen
combines right 3 think of microphone
spot but the end of the day from this
reactant every way to hydrogen it's also
called dehydrogenation reaction correct
this is also used to test actually
whether it is primary secondary or
tertiary alcohol why because if I take 1
degree alcohol
right way to oxidation it will give me
earlier if I do further oxidation being
carbon sorry gasps I'll show you three
actions if I take two degree alcohol if
I do
oxidation I got heat on you see here I
got ketone here right this is a studio
alcohol and here if you see one degree
alcohol I got early heights and then
whatever I did I got this is one degree
student ketone and further if you
oxidize you're getting a carboxylic acid
three degree alcohol if you have if you
try to oxidize there is no reaction
trade your 3d toe shoe your call it
doesn't undergo oxidation why because
there is no beta carbon rgvida hydrogen
- remove the hydrogen right there is no
hydrogen here in fact in this you can
also add copper and eighty this is also
used as a strong oxidizing eject so
let's see some of the reactions here
example I have are ch2oh and then I add
cro3 it is actually a weak oxidizing
agent you get our co h but same our
ch2oh if I add kmno4 right in acidic
medium or NH + after that I get our co h
right both case we are doing the
oxidation but depends on with a Las
Vegas agent is weak or strong so let's
see more reactions I have CH 3 CH that
was born
ch ch 200s I add BCC it's a weak
oxidizing engine so what will happen in
I will get something like this co h
correct let's stick one secondary
alcohol oxidation so i CH 3 you see is 3
o H they oxidize it I get ketone here
right this will be a become ketone and
there will be a shear actually yeah
and then I will further oxidized it what
we'll get is ch3 Co H and H cos that's
what we'll get okay so please not
tertiary alcohol right under normal
condition they does not undergo
oxidation why because it doesn't have
the alpha hydral alpha hydrogen is not
there because if you see here this is
alpha hydrogen it has to be there right
to be removed that is not there instead
of H has a mile group to remove two
hydrogen right this will not be there so
under the extreme conditions only it
goes oxidation will not study what that
uh nobody if you want IND be one
reaction very very extreme condition so
this is ch3 ch3 this metal your cop this
oxidation underscore my trigger said
very extreme condition you get something
like this and then further oxidation you
lose you can do further oxidation this
we have done actually this is same as
this alright also heated copper is used
for oxidation for example I have our
ch2oh so instead of cro3 I could have
used copper also and 573 Keller know
there is a heated god correct
you can write one reaction if you want
our CH R - o H you have copper heat you
get R 0 R - correct so we see that this
is oxidation let's see this reaction B
is an oxidation number so let's see this
reaction and we will see the oxidation
number difference right ch3cho H and
edge then you oxidize this this becomes
ch3cooh correct
if further oxidized this it becomes
ch3cooh let's see this is carbon one
this is carbon two list changing number
just to find oxidation number for carbon
one lets up alright let's write here
carbon one CS 3 will be 0 0 + o H minus
1 will be minus 1 2 hydrogen will be
plus 2 and this carbonyl it's as you
means X is equal to 0 you find the value
of x X comes out to be minus so here
oxidation numbers minus 1 let us do for
this guy Cochran - so this is ch3 is 0
plus this o is minus 2 H 3 and this
hydrogen is plus 1 plus X is equal to 0
you saw you get X s plus 1 so you get X
s plus 1 here solve for this way ch3 is
0 o is minus 2
Oh H is minus 1 plus X 0 you solve X X
comes out to be 3 so if you see the
oxidation numbers changed from minus 1
to plus 1
and thus if you see that this is the
oxidation reaction okay you can do it on
any ax and here also you can see two
very media action you'll see that the
oxidation number is increasing from left
to right and that's why it's called
oxidation thank you visit our website
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