Physical Properties of Amines Video Lecture | Chemistry Class 12 - NEET

hello friends this video in our minds
part 15 is brought to you by exam fear
calm no more fear from exam let's
understand nor physical properties over
me
we have known the law understood how to
name that means and how to prepare a
means let's understand the physical
properties of a meal so if you see the
lower ones the lower means for example
CH 3 NH 2 right
C 2 H 5 NH 2 methylamine in our mind
these are gases the lower ones are gases
three or more they are either liquids or
the higher ones up in soil so so we have
amines in the gas state liquid state and
solids it all three states right so we
know three one or two maintainer mindful
of mind these are all gases and then we
have liquids amines then we have solids
a means to any lien which we know is
this way and other
rila means they have generally colorless
but they get colored due to atmospheric
oxidation please note there is only
colorless but this due to atmosphere
oxidation the hits and colors and we
talked about the boiling point of these
amines the primary and secondary amines
are engaged in inter molecular hydrogen
bonding but not touch me because if you
see in this metal Cherie and then they
all are there is no bonding Ashley but
but it is my primary amine this hydrogen
has slightly positive charge this
Michael has slightly negative charge so
there is a bond here right so there has
to be some hydrogen attached to this
nitrogen that means it has to be their
primary amine with two hydrogen
second we had amine with
one hydrogen then only this hydrogen
want come into picture right so please
note primary and secondary mean primary
with NH to form our NH 2 or second ring
our 2 NH form each of this is hydrogen
they have intermolecular hydrogen bond
correct and with that they have higher
boiling point and please note that this
font is more in primary amine why
because they are too high to mr. Bhagwat
in secondary amine one hydrogen to form
on and in tertiary amine no hydrogen to
form a bond
the primary amine will have higher
boiling point why because the
intramolecular force between them is
most hope you understand two hydrogen
bond more two hydrogen's more hydrogen 1
1 hydrogen less have you want 0 hydrogen
no hydrogen 1 all right more the
hydrogen bond higher is the boiling
point see tertiary amine they don't have
intermolecular attraction between them
because there is no hydrogen atom
available for mourning because it is all
this form n R 3 since there is no
hydrogen atom attached for attach this
nitrogen for bonding so there is no
hydrogen bond so if you see the boiling
point order primary one has the highest
boiling point why because they have two
hydrogen attached to it and they have
large extent of hydrogen bond secondary
one has one hydrogen attack otama - 2
it's they are less extent of hydrogen
bond tertiary no hydrogen attached to it
so it has almost no hydrogen bond see
the boiling point dense less more
stronger the bond more tightly coupled
this particular compound is and more
strongly coupled this compound is more
is the boiling point because more energy
is required to break them correct see if
they are United you need more energy to
break them that means the boiling point
is high even more and more energy to
heat them up
for them but if they are not invited you
can even by warming up you can segregate
them correct let's do a comparison of
boiling point of these different
compounds is the same or similar
molecular mass so we see the one with
which has the maximum boiling point
because oxygen is more electronegative
than carbon and always difference is
more than any stiffness which always has
stronger hydrogen bond and this avoid
she'll always have stronger hydrogen
bond since the hydrogen bond is stronger
they'll have higher body and then comes
primary amine because it has two
hydrogens to form one and then comes
secondary amine mu C which has one
hydrogen and then comes a tertiary amine
at least there is some electron already
difference and here
normal alkali so hope you listen why
because if it is H here are H here is
again ROH air will form a stronger bond
the bond is stronger correct because
oxygen is more electronegative so
generally typically you will see alcohol
will have maximum boiling point because
alcohol is OS thing the next is the
solubility see the lower our minds are
water soluble because as I told them
they form hydrogen bond with water
molecule so if I have let's suppose CH 3
NH 2 then if I have water molecule here
slightly negative slightly positive it's
little form a bond correct it will form
on
the more Hydra molecule it's of course
you form a bond will be hydrogen bond
actually correct so the lower ones are
solid where this part is water insoluble
but if we keep increasing this mass
right so only this part will not be able
to take the NH two part will not be able
to take the load of this whole our part
here so this are so in that case the
higher molecules are higher our minds
will become water insoluble right if you
see the solubility decrease as you
increase the molar mass because this
part the our part is the hydro phobic
alkyl path all right so only this part
is water soluble so if this part is
small this part will take care of then
s2 part will take care of this alkyl
part smaller oil part but in this part
is big example you have something like
this you add more stuff shape you begin
with bulk here something like this so
only this part is water soluble and this
bulky part is not water soluble so even
if this part is water soluble this part
is not soluble so overall it is not
soluble correct so as you go up as we
increase the molecular mass of this
amines it becomes less water salt we
have seen similar kind of trend in the
other chakras where we have talked about
ketones aldehydes similar pattern here
also right cbc hi enemies are almost
insoluble in water but these amines are
soluble in organic solvent alcohol ether
busy correct why because alcohols are
more polar than amines and form stronger
intermolecular hydrogen bond energies so
these amines the lower amines the
solvent water
the medium are sparingly soluble the
higher amines are water insoluble
why because the water
part is ns-two part only or NH part
depending on there is primary or
secondary me and if you increase the
alkaline part the hydrophobic alkyl part
overall the compound becomes water
insoluble let's talk about the smell of
the means the lower aliphatic amines
they have fishy smell they're gasses and
they have fishy smell but the higher
ones they don't have strong water they
don't have strong water they are okay
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