Enthalpy during phase change - Thermodynamics Video Lecture - Class 11

hello friends this video on
thermodynamics part 9 here is brought
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exam before watching the video please
make sure that you have watched part 1
on 18 thanks tribe or the enthalpy
change during phase transformation as I
told our phase transformation involves
energy change right so if it goes from
solid to solid ice to liquid water
liquid and vapor gas stage moves from
solid liquid to gas there is a enthalpy
change in this egg because example if
you see ice requires heat to mend and
requires further more heat to become
steam as the magnitude of the enthalpy
change here for this phase
transformation it all depends on the
intermolecular interaction within some
cells because there is no chemical
reaction happening so the phase
transformation or the enthalpy change
depends solely based on the
intermolecular interaction if it is very
strong it will take more energy more
enthalpy changes if the strong bond is
weak it will less energy less the
enthalpy change mean less so if you see
for example in this case I have acetone
in water so it requires very less energy
to vaporize one mole of acetone then to
vaporize water because water we have
something on hydrogen bond which we have
learned in the past charter so because
of this the intermolecular force
attraction is high and water needs more
energy to evaporate one mole of water
then the energy required to evaporate
one mole of Osito
so we have different types of enthalpy
there minsky for fishing the first is
fusion so in case of fusion if you see
there is a phase change from solid to
liquid right so solid
so you see solid to liquid cementing of
solid liquid vice-versa actually both
side and this is called enthalpy of
fusion so you take one mole and you
change the state of solid to liquid or
liquid to solid then we talking about
enthalpy of fusion please note the
melting of solid is always in the
something that it needs energy so it is
always positive the main thing is all
the motion this side is always needed he
needs this so the red line is always
positive vaporization if you see it
gives me this liquid and gas
you see it ends with liquid and gas one
whole and standard condition that is
called enthalpy of vaporization so we
have this back up here then we have
sublimation when we talk about direct
change within the gas and solid the
liquid state doesn't even come so we
have solid substance that sublimes to
gas at constant pressure and sound
pressure we take one rule of that and
then we talk about the theory of
solution all think the same just
introducing you these terms are the
addition we are familiar with is
enthalpy of change of a few sermons
animation some of them and then this
table which is the chemist has created
morning and defenders this is what the
enthalpy change of the fusion fusion and
vaporization or various substances your
standard values thank you
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