Mixture & Pure substance - Some Basic Concepts of Chemistry Video Lecture - Class 11

hello friends this video on basic
concepts of chemistry part 3 is brought
you by exam viacom no more for you from
exam before watching this video please
make sure that you have watched part 1
and part 2 the matter at macroscopic
level can be divided into pure substance
and mixture then pure substance is
something which has fixed composition
we'll explain that very little
composition and make sure is something
where it is any de chinon version please
note it's all about on the basis of
composition this remind if the
composition is fixed the ratio perfect
when it is pure substance the ratio is
not fixed it is mixture right and the
pure substance can further be classified
into elements and compounds and mixtures
can be classified into homogeneous and
heterogeneous mixture will study more on
these but this is just a verbal view of
the matter matter is divided into pure
substance and mixtures pure substance is
divided into elements in compound and
mixture divine to homogeneous mixture
and heterogeneous nature correct to
start with pure substance pure substance
has a fixed composition as I told in
fact pure substance should have a fixed
accomplished example copper gold silver
water in fact glucose they are some of
the examples of the pure substance
because they have fixed formation if I
talk about compared suppose it has
helped us in cover talk about pure
problems if I talk about glucose it has
some carbon hydrogen and oxygen right it
has fixed composition of carbon hydrogen
losses we'll explain more on these
example as I told right this glucose has
fixed composition of carbon hydrogen you
can see sugar for example is c12 h22 o11
so we will study that if you take let's
suppose 10 grams of sugar the percentage
of carbon is fixed the percent of
hydrogen is fixed oxygen is fixed that
is true for any sugar right and that
is why they are called fewer substan
because the composition is fixed right
if you dig pure copper they'll always
have hundred percent if you take pure
gold it will happen it doesn't feel good
similarly water if you see so
composition of hydrogen and oxygen is
same for any water mole you take any
water molecule it will have two moles of
hydrogen and man will love us and the
pure substance can further to classify
into elements and compounds and you see
elements they have only one type of
watering is for example sodium copper
silver hydrogen oxygen and so these have
only one type of particle example sodium
will have only sodium copper will have
only copper Slavonic silver but in case
of compounds you see multiple atoms more
than two atoms combined to form come up
example ammonia nh3 so here mitogen
hydrogen ions are atoms are combined to
form ammonia water if you see h2o
hydrogen oxygens are combined to form
water so here if you see c12 h22 o11
carbon dioxide co2 CVC here carbon
hydrogen oxygen molecules that are mined
here carbon oxygen bond is combined so
the compounds are formed generally when
you combine more then two are more than
two different elements correct but if
you see in both the cases
the composition is fixed right so in
this case also water molecule also if
you see is the two mole of hydrogen one
mole of oxygen it will understand more
about moles in the next few slides
understand up composition is fixed you
take any copper nitrate to have same
composition of carbon same composition
of oxygen percentage-wise right so in
case of water also you take any water
molecule and have same composition
hydrogen and oxygen and that's why they
got pure subshells you talk more about
compounds you should know that the
property of compounds are very much
different from the elements for which it
is composed of example hydrogen oxygens
are the gases but water which you make
from hydrogen gas oxygen is a liquid
right example EVC h2 and o2
gives h2o
this guy's guys this guy's guys in this
guy's lingual so the properties are
totally different so you can tell the
properties will compound just by looking
at the elements or the property of
elements will not help you find the
property come on the totally different
correct although you see hydrogen burns
in a pop song and oxygen is supporter of
combustion if you see both our supporter
of combustion right hydrogen ransom but
water is a fire extinguisher water
dilemma see the the physical property is
not matching the chemical properties of
an automatic hydrogen oxygen both
supports combustion but water is not
supporting combustion it's again it is
it it is used as fire extinguisher
actually also please note if you have a
compound you can't separate out the
elements from the compound just by
physical method for example you have
water you cannot heat with hammer or you
can't pass this guy with a sheep or
something right with the physical
physical method you can't take out
hydrogen nozzle for that chemical
process has to be involved right so
there has to be chemical method which
will convert water into hydrogen and
oxygen media electrolytes do something
but there has to be chemical method
Mission convert this guy into elements
correct if you have a compound you can
simply use physical method to convert
them into knowledge signatures water
mixtures the name it's a mixture if you
see we eat a lot of these mixtures in a
home right so the mixture is named as
exactly the same as what it is so you
see in this case the constituents are
mixed in any issue so if you buy a
mixture formulate suppose healthy nam is
a brand healthy nam and if you buy
mixture from let's suppose another brand
ABC brand and I'm gonna make sure you
brand from little because there are
three brands right and one make sure you
brand from local shop local shop if you
see in all this make sure the constant
will be different in this case may be
the Bahama is high in this case may be
the puja is high in this case may be the
spice is more so there is no different
composition for mixture there is no law
that says that the mixture which we eat
in the home has to have this much amount
of bodom this was a box of booyah so the
ratio is not fixed and that's why they
call mixture right so you have to have
more substance you make a mix it and you
make sure that the ratio is not text for
example the air here in one city maybe
lipstick Mangler it has more pollution
so maybe sulfur so2 co2 is bored and you
in Delhi will be furthermore if you go
to a village the area's fresh it will
have less concentration of sulfur and
oceans right so it depends on CDC to
city place-to-place country to country
so air is something which is mixture why
because the the percent composition of
air for example percentage of co2
percentage of assume two percentage of
nitrogen those things in the gas there's
not same cross in some place it is more
in some places then that's why you see
that some cities the air quality is not
good in the village air quality is good
because in air in the village those pala
tents are less so air is one example
where you see the percentage composition
is not same across same thing is you
take a server solution right sure you
see speaker solution you don't define
that it is how much sugar it how much
water so you talk about sugar solution
sugar solution can also be a 1 teaspoon
1 teaspoon sugar in 1 liter you can make
a single solution by 1 teaspoon in 2
liter or two liter any of these we call
the silver solution right so the the
ratio is not fixed or you see the piles
and stone if you mix right if you buy
some good quality of pearls you may not
given gate stones but if you find the
bad quality pearls we get more stones
right so the ratio of pulse and stone in
any pulse is not fixed right so that way
they are called mixtures right because
the ratio is not fixed
make sure maybe a homogeneous or
heterogeneous I'll tell you what is
homogeneous and heterogeneous not in a
homogeneous mixture the components are
mixed with each other and its
composition is uniform throughout
if you talk about air of a village
particular village eggs if you go to any
corner of the village right or if you
take air in a jar from a particular city
you'll find that the composition of co2
composition of so2 they are mixed
uniformly they are mixed uniformly right
it's all uniform but air as a global
thing is not uniform because you take a
mix air of bang or a of Delhi air of a
village here let suppose we can air the
air quality is not thing right so that's
why air is not not a element or compound
right it is not pure it is mixture but
if you take air in a jar you'll see that
things are uniform in this distributed
right the percentage of carbon bikes if
you take a from this area a from this
area or a from this area from a Java
example you put the air in a jar and now
if you take here from this area you take
a from this array from this area the
percentage composition will always be
almost be same and that's why they are
homogeneous because they're uniformly
mixed they completely mix em uniformly
but super solution also you make a super
big server solution let's suppose tell
it or a super solution and then you even
need to take one T's 1 ml from this or
Manimal from this area one model from
this area in all these you'll find the
same percentage of sugar right if it is
uniformly mixed and that's why they are
called homogeneous mixture but in
heterogeneous mixture the composition is
not throughout for example you have a
boogie right you take out from you take
this much portion you see you get more
but now because they are tuba not you
take the same thing from this material
you see there is no the gamma tall right
if you take from this area you see
you'll find a green leaves but if you
take from this area you'll not find any
leaves so that means you take a sample
from a bigger one you'll find that you
take n samples you you will find that in
all these examples the percentage of
different constituents in this case
bhujiya padam are not saying like and
that's why they called heterogeneous
heterogeneous means it is not uniform
throughout where it is not uniform
through example mixture of Dalmore
bhujiya bahama etcetera the examples I
give
correct and in this case the component
of the mixtures can be separated using
physical methods such as let's suppose
hand picking so you have make sure you
do hand raking you can separate all the
bath arms you can separate all the
picture that you can do that it may take
time but that'll I do able thing
filtration you can do it from
distillation or you can do it for
example this salt and water you have you
can crystallize and you can take out
again salt that so sugar back from the
solution from distillation also you can
do example Melinda what really makes you
can take out the mud from the salacious
so in a case of make sure you have you
can take out the constituents or you can
separate the consecrate using physical
method also but in case of pure elements
or compounds it is not possible for that
a chemical method has is required to
separate out stars correct thank you
visit exam viacom to watch free
educational videos try free online tests
get the best quality study materials
show you from the best tutors and
mentors and much more thanks else again