Laboratory funnels are funnels that have been made for use in the chemical laboratory. There are many different kinds of funnels that have been adapted for these specialized applications. Filter funnel

Filter funnel

A filter funnel is a laboratory funnel used for separating solids from liquids via the laboratory process of filtering.In order to achieve this, a disk shaped piece of filter paper is usually folded into a cone and placed within the funnel. The suspension of solid and liquid is then poured through...

s, thistle funnels (shaped like thistle

Thistle

Thistle is the common name of a group of flowering plants characterised by leaves with sharp prickles on the margins, mostly in the family Asteraceae. Prickles often occur all over the plant – on surfaces such as those of the stem and flat parts of leaves. These are an adaptation that protects the...

 flowers), and dropping funnel

Dropping funnel

A dropping funnel is a type of laboratory glassware used to transfer fluids. They are fitted with a stopcock which allows the flow of to be controlled. Dropping funnels are useful for adding reagents slowly, i.e. drop-wise...

s have stopcocks which allow the fluids to be added to a flask slowly. For solids, a powder funnel with a wide and short stem is more appropriate as it does not clog easily.

When used with filter paper

Filter paper

Filter paper is a semi-permeable paper barrier placed perpendicular to a liquid or air flow. It is used to separate fine solids from liquids or air.-Properties:Filter paper comes in various porosities and grades depending on the applications it is meant for...

, filter funnels, Buchner

Büchner funnel

A Büchner funnel is a piece of laboratory equipment used in suction filtration. It is traditionally made of porcelain, but glass and plastic funnels are also available. On top of the funnel-shaped part there is a cylinder with a perforated plate separating it from the funnel. The Hirsch funnel has...

 and Hirsch funnels can be used to remove fine particles from a liquid in a process called filtration

Filtration

Filtration is commonly the mechanical or physical operation which is used for the separation of solids from fluids by interposing a medium through which only the fluid can pass...

. For more demanding applications, the filter paper in the latter two may be replaced with a sintered glass frit.

Separatory funnel

Separatory funnel

A separatory funnel, also known as separation funnel, separating funnel, or colloquially sep funnel, is a piece of laboratory glassware used in liquid-liquid extractions to separate the components of a mixture between two immiscible solvent phases of different densities Typically, one of the...

s are used in liquid-liquid extraction

Liquid-liquid extraction

Liquid–liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds based on their relative solubilities in two different immiscible liquids, usually water and an organic solvent. It is an extraction of a substance from one liquid phase into another liquid...

s.

Construction

Glass is the material of choice for laboratory applications due to its inertness compared with metals or plastics. However, plastic funnels made of nonreactive polyethylene

Polyethylene

Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...

 are used for transferring aqueous solutions. Plastic is most often used for powder funnels which do not come into contact with solvent in normal use.

The types of funnels in the laboratory

• Plain funnels exist in various dimensions, with longer or shorter necks.
• Filter funnel
  Filter funnel
  A filter funnel is a laboratory funnel used for separating solids from liquids via the laboratory process of filtering.In order to achieve this, a disk shaped piece of filter paper is usually folded into a cone and placed within the funnel. The suspension of solid and liquid is then poured through...
  
  s 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.
• Separatory funnel
  Separatory funnel
  A separatory funnel, also known as separation funnel, separating funnel, or colloquially sep funnel, is a piece of laboratory glassware used in liquid-liquid extractions to separate the components of a mixture between two immiscible solvent phases of different densities Typically, one of the...
  
  s are pear-shaped, have a cap and a short neck, with a stopcock for the even pouring of fluids. These are used to decant two immiscible fluids. It can be graduated, though this is not very common.
• Hirsch funnels are shaped much like normal funnels, but contain holes or sintered glass at the base for quick filtrations.
• Dropping funnel
  Dropping funnel
  A dropping funnel is a type of laboratory glassware used to transfer fluids. They are fitted with a stopcock which allows the flow of to be controlled. Dropping funnels are useful for adding reagents slowly, i.e. drop-wise...
  
  s are a cylindrical, regularly graduated funnel with standard taper ground glass joints. These are often supplied with a pressure equalizer.
• Buchner funnel
  Büchner funnel
  A Büchner funnel is a piece of laboratory equipment used in suction filtration. It is traditionally made of porcelain, but glass and plastic funnels are also available. On top of the funnel-shaped part there is a cylinder with a perforated plate separating it from the funnel. The Hirsch funnel has...
  
  s are made of porcelain and include a plate of sintered glass or perforated porcelain. These are used in filtration under low pressure with a Buchner flask
  Büchner flask
  A Büchner flask, also known as a vacuum flask, filter flask, side-arm flask or Kitasato flask, is a thick-walled Erlenmeyer flask with a short glass tube and hose barb protruding about an inch from its neck. The short tube and hose barb effectively acts as an adapter over which the end of a...
  
  .
• Hot filtration funnel is a less commonly seen funnel where the funnel is jacketed, and surrounded by a heated fluid.