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VACUUM FILTRATION PowerPoint Presentation
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  1. VACUUM FILTRATION Yuson will show you how to do a vacuum filtration. Scroll down.

  2. VACUUM FILTRATION STEP #1 Clamp a filter flask so that it rests on the base of a ring stand.

  3. VACUUM FILTRATION STEP #2 Buchnerfunnel Select and insert a piece of filter paper that just fits the bed of the Buchner funnel.

  4. VACUUM FILTRATION STEP #3 Place a Filtervac adapter on top of the flask, and set the Buchner funnel into the adapter. Attach a thick-walled hose to the side arm of the flask. Connect this hose to a trap, as shown in the next step.

  5. VACUUM FILTRATION STEP #4 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. Do not turn the water on yet. to the filter flask

  6. THE TRAP IN USE DURING FILTRATION In steps #5-6, there will be a vacuum when you turn on the aspirator faucet and close the system with a pinch clamp.

  7. 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.

  8. 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.

  9. VACUUM FILTRATION 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

  10. VACUUM FILTRATION STEP #7 Continue if necessary to filter the rest of the mixture in fairly 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.