the chemical equilibrium attention in
this video hazardous chemicals are used
I don't take any responsibility for
damage done to persons or property
caused by the recreation of these
experiments for this experiment a glass
ampule have been filled before with
nitrogen dioxide in addition to that two
beakers were prepared with ice water and
hot water in the hot water the gas
becomes more darker while the color
becomes more pale in the ice water this
happens because the brown nitrogen
dioxide exists in an equilibrium with
its colorless diamond dinitrogen
tetroxide at high temperatures the
equilibrium shifts to the left at a
lower temperature to the right this can
be explained with lechatelier's
principle when a system at equilibrium
is subjected to a change it changes to a
new equilibrium to minimalize the effect
of the change in this case the effect is
achieved by changing the temperature the
enthalpy of reaction of the forward
reaction is negative which means that
it's exothermic when the gas is cooled
the equilibrium shifts to the right
while energy is released to act against
the cooling the enthalpy of the reverse
reaction is positive so it's endothermic
this causes the equilibrium to shift to
the left in the hot water to act against
the increasing temperature for the next
experiment two solutions were prepared
for the first one 8.11 grams of
anhydrous iron 3 chloride were dissolved
in 50 milliliters of distilled water
other soluble iron 3 salts could also be
used but the amount has to be adjusted
the mixture was put aside after stirring
because it takes a while for the salt to
dissolve for the second solution 0.46
grams of potassium thiocyanate were also
dissolved in 50 milliliters of distilled
water both solutions should have a
concentration of around point 1 moles
per liter
the ayran chloride had insoluble
impurities so it was filtered the field
trade didn't look more clear in reality
but our
three chloride also tends to slowly
hydrolyze for the experiment this
solution is sufficient next 10
milliliters of each of the solutions
were mixed together I really like the
following reactions so the iron 3
chloride solution was added with a
pipette first the iron 3 ions and the
thiocyanate react to form the deep red
iron 3 thiocyanate then the rest of the
solution was added
after that the solution had to be
diluted until it had an amber color
where it proved to be more efficient to
dilute only a milliliter or two the red
color was so strong that it would have
been better to take only a small portion
of the diluted solution and eluted
further next three test tubes were
prepared each with five milliliters of
the diluted solution to the first one
five milliliters of the thiocyanate
solution were added obviously the color
became more intense to the right sample
five milliliters of the ayran free
solution were added the effect was not
as strong but it could be seen that the
solution became darker the iron three
and fire cyanide ions exist in an
equilibrium with the iron three
thiocyanate in an equilibrium the
reactions have not stopped the speeds of
the forward and reverse reaction are
just the same making it seem as if the
reaction is over the law of mass action
describing this reaction looks like this
the equilibrium constant KC is
calculated by multiplying the
concentrations of the products and
dividing it by the product of the
concentrations of the edicts
stoichiometric numbers like the three in
front of the thiocyanate ions are added
as exponents so for example when the
concentration of the thiocyanate is
increased the concentration of the iron
thiocyanate has to increase so that KC
does not change the exponent of the
concentration of the thiocyanate causes
it to have an higher effect on the
equilibrium than the iron three ions
the law of mass action can also be used
to describe equilibria of gases where
the concentrations are replaced by the
partial pressures and the equilibrium
constant is called KP this was the
chemical equilibrium I hope you enjoyed
please rate and comment if you want to
see a synthesis that involves the
chemical equilibrium
you can watch the synthesis of ethyl
formate here or you can watch my latest
video here a big thanks to my supporters
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