Funnel And Filter Paper Chemistry

Flute filter paper if necessary.

Funnel and filter paper chemistry.

Place the funnel either directly on top of the beaker or on a ring stand above the beaker see figure 1 below. A filter funnel is a laboratory funnel used for separating solids from liquids via the laboratory process of filtering. Saves time required to fit circles into conical funnels. Removing unwanted solid from liquid is the basic function of a büchner funnel.

Some scientific funnels are designed to channel powder rather than fluids. Plain funnels exist in various dimensions with longer or shorter necks. Whatman grade 2v folded qualitative filter papers provide medium flow and nominal particle retention rating of 8µm at a higher filtration speed. Filter funnels have a neck of a thin capillary tube and ribs which increase the filter papers effectiveness and thus accelerate the process of filtering.

Powder funnels have a small and wide neck for fast pouring of powders. Filter papers are often used to filter fine particles out of a liquid being transferred. When placed in the funnel the paper should not be shorter than the top of the funnel or the solution might slip past the filter paper when poured. The arrows show the direction of folding.

Filtration operations in general chemistry involve crystalline precipitates of relatively large crystal size so that coarse or medium porosity filter paper is used. In order to achieve this a cone like shaped piece of filter paper is usually folded into a cone and placed within the funnel. Fluting is desirable when a rapid filtration is necessary as in the filtration of the hot solution during a recrystallization. Some funnels contain stopcocks which slow down the rate at which a fluid runs through a funnel.

The dotted lines represent locations to crease and fold the filter paper. The suspension of solid and liquid is then poured through the funnel. It blocks the solid particles and the remains are passed into the collecting flask. The mixture of the liquid and solid is passed through the filter which also has a piece of filter paper in the funnel acting as a filtering agent.

Separatory funnels are pear shaped have a cap and a short neck with a stopcock for the even. Sargent welch s 32915 whatman 1 and e d 617 have appropriate pore size for work in this course. The justrite large steel drum funnel with self closing cover helps to prevent spills when transferring flammable solvents thinners oils or paint wastes. Specialty funnels exist for use in scientific laboratories.

Place filter paper in the funnel.