Factors Affecting Solubility of Substances Video Lecture | Science Class 6

and this we're going to learn about
factors that affect solubility try this
experiment at home or at least think
about what would happen if you did try
this experiment take some sand and stir
it into a glass of water and what
happens
well the sand just kind of settles to
the bottom now try taking some salt and
stirring that into a glass of water what
happens this time while it disappear it
dissolves some things are able to form
solutions with water and other things
are not the sand did not dissolve and so
it is insoluble and the salt on the
other hand it did dissolve and so this
is soluble and so in this video we're
going to learn about what affects the
solubility of things that dissolve in
water why do some things dissolve better
and how can we make something dissolve
better so we're going to look at four
factors will look at stirring
temperature particle size and pressure
now before we get to those one thing to
consider is that solids are not the only
thing that can dissolve in water believe
it or not gases dissolve in water as
well and actually air dissolves into
water really well if you drink a glass
of water you're not drinking pure water
you're drinking water that contains a
lot of dissolved substances now some of
those things are minerals and different
vitamins that might have dissolved in
there have been intentionally placed in
there but you're also going to get air
that's in there so the oxygen and carbon
dioxide and nitrogen from the air
dissolves into that water you can also
think about pop-pop is fizzy because
they have put dissolved co2 into that
pot gives it that fizziness so we're
thinking about solubility we're thinking
about solids we're also thinking about
gases in some of these so let's start
with stirring this one's pretty
common-sense have you ever tried to
sweeten your tea or coffee with a
spoonful of sugar well you can't just
dump it in and let's start drinking you
have to stir it now if you did just dump
it sugar in it would eventually dissolve
it would just take a long time so
stirring increases the rate at which a
solid will dissolve so another way to
put that is we could say stirring
increases the rate
of the solubility next factor that we'll
look at is temperature now iced tea and
hot tea are going to dissolve sugar
differently you may have tried stirring
sugar into iced tea to sweeten it a
little bit and after you finish that
whole glass of iced tea you may have
noticed that there's a bunch of sugar
left in the bottom or maybe you notice
it was sweeter at the bottom than it was
at the top solids don't dissolve very
well in cold water and the hotter the
water the faster or the more of a solid
you're going to be able to dissolve now
what about gases well gases actually
work the opposite you know hot solution
gases will dissolve less or they'll be
less soluble and so solids are going to
increase their solubility as the
temperature increases while gases will
decrease their solubility as the
temperature decreases all right the next
one here is going to be particle size
now there is a reason we use granulated
sugar to add to our tea and coffee
the smaller the particle size the faster
a substance will dissolve and breaking a
substance into smaller particles gives
more surface area to interact with the
water molecules and dissolve and so the
smaller the particle the faster it will
dissolve and finally pressure now
increasing the pressure of a solution is
kind of like pushing down on the top of
the solution this has very little effect
to no effect at all on the solubility of
a solid solids aren't affected by
pressure gases on the other hand are
greatly affected by pressure the greater
the pressure the greater the solubility
of a gas and this is why pop goes flat
when it's left open the reason pop is so
packed with co2 is because it's under
great pressure that's what it means to
be carbonated is that they pressurize
the solution and they can pack a whole
bunch of carbon dioxide into that
solution it makes it all fizzy and when
you open the bottle up up you're going
to lower the pressure of the solution
and so the solubility of the co2
decreases and the PAH
we'll go flat and so those are the
factors that affect solubility