VACUUM FILTRATION
VACUUM FILTRATION STEP #1
Yuson will
show you
how to do a
vacuum
filtration.
Scroll down.
Clamp a filter
flask so that it
rests on the
base of a ring
stand.
VACUUM FILTRATION STEP #3
VACUUM FILTRATION STEP #2
Buchner
funnel
Place a Filtervac
adapter on top
of the flask, and
set the Buchner
funnel into the
adapter.
Select and
insert a
piece of filter
paper that
just fits the
bed of the
Buchner
funnel.
VACUUM FILTRATION STEP #4
to the
filter
flask
Attach a thick walled hose to
the side arm of
the flask.
Connect this
hose to a trap,
as shown in the
next step.
THE TRAP IN USE DURING FILTRATION
Assemble a
trap, whose
purpose is to
catch water
that might back
up if there is a
change in
pressure.
Connect the
trap to the filter
flask.
In steps #5-6,
there will be a
vacuum when
you turn on
the aspirator
faucet and
close the
system with a
pinch clamp.
Do not turn the
water on yet.
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VACUUM FILTRATION STEP #5
(If your solvent is non-volatile,
you may use it to pre-wet the
filter paper.) Pour the first
portion of filtration mixture into
the funnel -- take care that the
paper doesn’t float up!
Turn on the water and close the
outlet hose with the pinch clamp
to start the vacuum. Proceed
immediately to step #6.
VACUUM FILTRATION STEP #6
If you don’t have a
vacuum, grasp the
sides of the funnel
and hold it down.
This should make a
seal.
Once there is a
vacuum, the liquid
will flow through
quickly.
VACUUM FILTRATION
VACUUM FILTRATION STEP #7
Buchner funnel
with filter paper
trap connected to the aspirator
(shown in the closed position)
Filtervac
thick -walled hose
filter flask clamped resting on the
base of the ring stand
Continue if necessary to filter the rest of the mixture in fairl y large portions.
At the end of the filtration, the liquid will have been sucked through and the
solid will appear quite dry (it actually won’t be completely dry yet).
You should open the pinch clamp before you turn off the faucet. Otherwise,
the vacuum may suck the water back into the trap.
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