All Topics  
Watch glass

 
Watch Glass

 
   Email Print
   Bookmark   Link
 

 

Watch glass
 
 
  Topics Watch glass Topic Home

A watch glass is a circular, slightly concave piece of glass used in chemistry
Chemistry

Chemistry is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions....
 as a surface to evaporate
Evaporation

Evaporation is the slow vaporization of a liquid and the reverse of condensation. A type of phase transition, it is the process by which molecules in a liquid State of matter spontaneously become gaseous ....
 a liquid, to hold solids while being weighed, or as a cover for a beaker
Beaker (glassware)

A beaker is a simple container for stirring, mixing and heating liquids commonly used in many laboratories. Beakers are generally Cylinder in shape, with a flat bottom....
. The latter use is generally applied to prevent dust or other particles entering the beaker; the watch glass does not completely seal the beaker, and so gas exchanges still occur.

When used as an evaporation surface, a watch glass allows closer observation of precipitates or crystallisation, and can be placed on a surface of contrasting colour to improve the visibility overall.

Watch glasses are so named because they are identical to the glass used for the front of old-fashioned pocket watch
Pocket watch

A pocket watch is a watch that is made to be carried in a pocket, as opposed to a wristwatch, which is strapped to the wrist. They were the most common type of watch from their development in the 16th century until wristwatches became popular after World War I....
es.






Discussion
Ask a question about 'Watch glass'
Start a new discussion about 'Watch glass'
Answer questions from other users
Full Discussion Forum



Encyclopedia


Caesium Fluoride
A watch glass is a circular, slightly concave piece of glass used in chemistry
Chemistry

Chemistry is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions....
 as a surface to evaporate
Evaporation

Evaporation is the slow vaporization of a liquid and the reverse of condensation. A type of phase transition, it is the process by which molecules in a liquid State of matter spontaneously become gaseous ....
 a liquid, to hold solids while being weighed, or as a cover for a beaker
Beaker (glassware)

A beaker is a simple container for stirring, mixing and heating liquids commonly used in many laboratories. Beakers are generally Cylinder in shape, with a flat bottom....
. The latter use is generally applied to prevent dust or other particles entering the beaker; the watch glass does not completely seal the beaker, and so gas exchanges still occur.

When used as an evaporation surface, a watch glass allows closer observation of precipitates or crystallisation, and can be placed on a surface of contrasting colour to improve the visibility overall.

Watch glasses are so named because they are identical to the glass used for the front of old-fashioned pocket watch
Pocket watch

A pocket watch is a watch that is made to be carried in a pocket, as opposed to a wristwatch, which is strapped to the wrist. They were the most common type of watch from their development in the 16th century until wristwatches became popular after World War I....
es. In reference to this, large watch glasses are occasionally known as clock glasses.