Deep evaporating dish of 18/8 stainless steel, 145 × 55 mm

A deep evaporating dish of 18/8 stainless steel measuring 145 × 55 mm, with a rolled rim, serves for evaporating solvent and concentrating solutions in laboratory work. The deep form takes a larger volume than a flat dish of the same diameter. A general-purpose laboratory product from the Laboratory accessories category.

The job of an evaporating dish is to remove the solvent and leave a dry residue or a concentrated solution. It works on a water bath and on a hotplate, because steel conducts heat evenly across the whole base and does not crack when the temperature changes suddenly. The rolled rim stiffens the edge, makes it easier to grip with tongs and keeps pouring tidy. At a diameter of 145 mm the evaporating surface is large, so the process runs faster than in a narrow vessel.

Heating is applied gradually, and the vessel is not left hot once all the liquid has evaporated, because an overheated residue can decompose. Steel is opaque, so the progress of concentration is judged by mass or by the look of the surface rather than through the wall. The 18/8 alloy is not suitable for long contact with concentrated acids and chloride solutions; porcelain or platinum ware is used for such work. After every use the dish is cleaned of residues, which are hard to remove once dry.

• Name and variant: deep evaporating dish with a rolled rim
• Dimensions: 145 × 55 mm
• Material: 18/8 stainless steel

How does a deep evaporating dish differ from a flat one?

By the volume it takes at the same diameter. The deeper form allows a larger portion to be evaporated in one go, while a flat one evaporates a thin layer faster.

What does a rolled rim give?

Stiffness at the edge and a surer grip with tongs, including when the vessel is hot. It also makes it easier to pour a concentrated solution without it running down the wall.

Can a steel evaporating dish be used with concentrated acids?

Not for long contact. The 18/8 alloy stands up to corrosion under typical conditions, but concentrated acids and chlorides leave pitting; porcelain ware is more appropriate for such work.