User:Chrissiejr/sandbox

Uses
Not only a watch glass can be used for observing precipitation patterns and crystals, it can also be utilised in drying solids. When further drying is required, a watch glass is often used in cases where a particular type of solid needs to be separated from its comparatively volatile solvent. The solid is spread on a watch glass and, often time, a folded filter paper is placed above to keep out airborne particles from contaminating the product. To maximise the drying rate, place the watch glass inside a fume hood to provide good air circulation for a adequate amount of time. Another technique used in chemistry laboratories to increase the drying rate is passing a gentle steam of dry air or nitrogen gas over the watch glass from an inverted funnel clamped above it.