Narration Japanese Page

12. Gravity Filtration

General Remarks

How to Operate Gravity Filtration


  1. Fold the filter paper into four and fit it into the funnel.
  2. When the filter paper does not fit well into the funnel, slightly adjust the folding in order to fit it perfectly.
  3. In order to make the filter paper fit perfectly, cut the edge of the over lapping filter paper in contact with the funnel obliquely. Wet the paper with the solvent and press with fingers to fit the paper in.
  4. Place a container in a manner that the leg of the funnel touches its inside wall.

Filtration and Washing of a Precipitate

  1. Put a stirring stick on the mouse of the container and decant a sample slowly.
  2. The filtration proceeds smoothly when the supernatant and then the mixture containing the precipitate are filtrated. Such operation is suitable when the filtrate is required.
  3. When the precipitate is needed, quickly pour the swirling sample onto the filter paper. Next, add the filtrate to the remaining precipitate in the container, and then pour the mixture onto the filter paper again.
  4. Wash the collected precipitate on the filter paper with a washing liquid a few times.

Dissolving the Precipitate

  1. Dissolve the precipitate on the filter paper by adding an appropriate reagent.
  2. Alternatively, put the filter paper on the inner wall of a beaker and pour the reagent repeatedly on the precipitate.