Naming aldehydes, ketones, carboxylic acids Video Lecture - Class 12 | Best Video for Class 12

I
this ice cream and cake Oh their
existence to chemistry don't shake your
head in disbelief because this is true
many aldehydes and ketones are used not
only in perfume industry but also as
commercial food flavoring agents for
example benzaldehyde is an aldehyde with
a characteristic almond like odor so
what's the role of these compounds in
our daily life let's find out in today's
episode
hi I am the brother Goswami let me
welcome you to another fascinating
episode of chemistry I am sure you have
eaten brightly colored food at some time
the bright orange jalebis come to mind
well if you go beyond the smell of the
perfume and flavor of your favorite dish
you will find chemical compounds lurking
there one class of such compounds which
are used as flavoring agents are known
as aldehydes and ketones in this episode
we will discuss general methods of
preparation of aldehydes and ketones
further down in the episode i will
discuss important chemical reactions of
aldehydes and ketones and finally we
will look at the important questions in
the exam decoded section so what are
aldehydes and ketones well these are
special organic compounds in which a
carbon atom shares a double bond with an
oxygen atom the double bond between
carbon and oxygen is characteristic of
all aldehydes and ketones and as you
know is known as the carbonyl group so
what is the difference between an
aldehyde and a ketone well an aldehyde
contains at least one hydrogen attached
to the carbon of a carbonyl group
whereas a ketone contains two alkyl
groups attached to the carbon of the
carbonyl group remember at the beginning
of the show we talked about aldehydes
and ketones being used in many food
products to add frag ninh seas and
flavor why do you think that is so well
many aldehydes have pleasant odors
benzaldehyde is one such aldehyde at
room temperature it is a colorless
liquid with a characteristic almond like
odor it is the primary component of
bitter almond oil extract you will be
surprised to know that aldehydes and
ketones can be prepared from many
different compounds but initially we
will prepare them from acyl chlorides
which are also known as acid chlorides
and this method of preparation is called
resonance reduction in this method acyl
chloride is hydrogenated over a catalyst
which is palladium supported on barium
sulfate a small amount of sulfur or
queen helene is added to the catalytic
mixture this is done to prevent
aldehydes from further reducing to
alcohols
now that we are done with preparing
aldehydes let's move on to ketones how
can they be prepared from acid chlorides
or acyl chlorides let's find out ketones
can be prepared by reacting SI chlorides
with dialkyl cadmium
dialkyl cadmium is prepared by the
reaction of cadmium chloride with
grignard reagent
after preparing aldehydes and ketones
from acyl chlorides it's now time to see
how nitriles are used in the making of
these chemical compounds let's begin
with aldehydes firstly nitriles are
reduced to corresponding amines by
reacting nitriles with stannous chloride
in the presence of hydrochloric acid the
email on hydrolysis gives the
corresponding aldehyde this method is
called stiffen reactions do you know
that a chemical reagent called die
isobutyl aluminum hydride is also used
to prepare aldehydes from nitriles this
reagent is also known as dible H let's
see what happens in this reaction here
nitriles are getting reduced to a means
by dye isobutyl aluminum hydride
he means then get hydrolyzed to
aldehydes just like aldehydes ketones
can also be prepared from nitriles let's
see how to prepare ketones a nitrile is
first reacted with grignard reagent in
the presence of ether
the product formed is hydrolyzed to give
us ketone
that was all very serious so let's take
a look at how aldehydes and ketones
affect our lives you must have seen
avalanches in some movie the sudden fall
of snow from mountain peaks in large
quantities is called an avalanche they
can be pretty dangerous and cause
massive destruction but chemistry has a
solution to this problem as usual let's
first figure out the reason these
avalanches happen as you know snow falls
in flakes which are actually crystals
rising water vapor gets attached to
these no crystals and freeze around its
corners and form large sparkly crystals
with cup-shaped facets these large
crystals are called depth horse they
make the glacier unstable as more and
more snow falls the glaciers can break
away and fall down the mountain as
avalanches but let's meet our hero
chemistry treatment with benzaldehyde
and n heptyl d I'd may prevent
avalanches caused by unstable depth hole
layers however these chemicals are not
in widespread use because they damage
vegetation and contaminate water
supplies
if learning about avalanches was a
chilling experience let's warm up now
with a different exercise till now we
learnt how aldehydes and ketones can be
prepared let's take a short break but
don't go anywhere because I am coming
back with some more interesting
chemistry for you but before going on a
break I have a question for you I am
sure you have seen camphor we use it for
medicinal purposes and also in religious
ceremonies do you know which functional
group is present in this compound you
can find the answer on www topple
learning com I will be right back with
all the answers and some more chemistry
you