Mole Concept - Some Basic Concepts of Chemistry Video Lecture - Class 11

hello friends this video on basic
concepts of chemistry part 12 is brought
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from exam before watching this video
please make sure that you have watched
part 1 to part 11 now let's take this
mole concept with critical concepts of
reading data engineer so can we guess
the number of moles molecules in a
warning gram of salt I have given one
gram of salt this much small salt can we
give the number of molecules in this yes
we can find it will be huge number right
so to handle such large number we need a
unit of similar magnitude right because
it will be some friend about 23 so to
get that we what we have is in the SI
unit we have mole this was introduced as
a seventh base quantity to handle such
huge numbers right because the numbers
are huge this mole was introduced in the
SI in a seventh base quantity this is a
seventh base quantity and this one mole
by definition of the word amount of
substandard contains as many particles
as they are in 12 grams of sequence if
you see we have standardized C to M and
that's why we are using C 12 as amis so
do you see you should take one gram of
hydrogen if that contains X atoms you
see that 12 grams of carbon will also
contains Exeter
you see that 16 grams of oxygen will
also consume like systems why because
the atomic mass of this number right
look for any number the atomic mass a
mass of element ABC will have X this
became proved also so see you take any
elements you take hydrogen atomic mass
is 1 so 1 gram of a atomic mass grams of
element ABC will have X atoms to take 1
gram of hydrogen to lamech systems take
2 grams of carbon atom X items would
exist in terms of oxygen actually why
because if you see to make one grams
right
you have one hydrogen atom right you
have one hydrogen atom that has one
proton you have carbon which has 12 so
you multiply 12 with that number we get
together grams each carbon each oxygen
atom is 216 grams you multiply with some
numbers it will get system that I have
not confusing this let's let's go into
this now this number is called a mega
dro constant this value is six point
zero two two realities that means you
say one mole of hydrogen will have this
many atoms you say one mole of water
molecule has this many molecules when
you say one mole of sodium chloride will
have these many roots of so divide this
number is very critical 6.0 2/3 so what
you observed was you if you take this
many molecules of hydrogen you get one
of them you take these many molecules of
carbon you get 12 and obviously why
because all the molecules of carbon are
12 times higher than hydrogen way
because it has 12 number of protons plus
neutrons so if if let's suppose hydrogen
are let us suppose a each molecule has a
weight right and you take you you take
six point zero two three into the power
23 this becomes one gram
now if you take carbon each molecule of
carbon is 12 P because hydrogen is a
this is raised to n times away you take
you multiply this guy this ligand 12
gram obviously because a into this is
one so 12 into this will be this is
nothing but six point zero two three
there's a complete wraps
similarly if you take oxygen each oxygen
molecule is 16 times of hydrogen into if
you say six point zero three you get 16
grams
correct same same formula because this
guy is 12 1 this guy becomes 1 16 to 1
becomes system so that's why it is the
general formula is you take atomic
of any element that supposed n the you
take engrams of that element that will
always have 6.0 to 3 into 10 to the
power 23 atoms and that's why this
number became very famous and that guy's
the number his name as away Gautreaux
constant honor of that chemist Avogadro
correct so one mole is nothing but
amount of substance that contain as many
particles as they are items in 12 gram
of carbonized and that is nothing but 6
into 6 point 0 to 3 into 10 to the power
23 atoms correct actually one gram of
hydrogen to a gram of chiral carbon 60
grams of auxin although they have almost
same number of atoms but this guy was
since c2l was taken the standard so the
definition is also in terms of c12 to
Aram some c2 will have six point zero 2
3 into 10 to the power 23 carbon atoms
let's understand a new topic called
molar mass molar mass is nothing but
mass of one mole of substance and it is
in grams and that will call will mask
you take one mole of any substance and
then you find the mass that in grams
that becomes important math right for
example my one mole is nothing but six
point zero two three you take this many
atoms of any anything for example let's
suppose oxygen right this will have some
gram for the 16 grams this becomes
smaller mass and typically if you see
the molar mass is nothing but but is
always equal to atomic or molecular mass
or the formula mass correct and there is
in grams because one mole of this guy
but these many atoms of oxygen will be
16 grams these many atoms of hydrogen
will be one grams right this here
explain the last slide so the molar mass
is really ramp and there is almost equal
to or equal to atomic mass or formula
mass form volatile mass for example
molecular mass of molar mass of oxygen
is 16
the molar mass of water is 80 why
because h2o 2 into 1 plus 60
similarly the molar mass of carbon is 12
the molar mass of sodium is 15 point 5
molar masses forgiveness Curie and this
is if you see the formula mass of so
molar mass is in gram please note
Bahamas in ramp and this is L equal to
your atomic mass or molecular mass on
that particular compound or element you
are talking about if you're talking
about element we talked about the atomic
mass you talk about compound two example
watery talk about molecular mass talk
about something like sodium chloride you
talk about four models and that is in
grams and this is nothing but the mass
of one mole of standards mass of six
point zero two three one two three atoms
of particular matter
right or this many molecules of
particular correct mask off thank you
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