Flame test

Description

A simple, visual qualitative test for some inorganic elements that is sometimes hard to interpret. When vaporized, every element has a characteristic set of emission bands which produce colors in the visible range. Flame tests have been used for over 200 years to distinguish the metallic cations in salts, minerals, and metals. For the test, a particle, the size of a pin head or larger, is heated in a flame to incandescence and observed to determine its emission color. The following list provides some visible range emission flame colors with corresponding elements:

- Violet: Potassium, Rubidium, Cesium

- Pale blue: Lead, Arsenic, Selenium

- Blue-green: Copper salts with halides

- Green-blue: phosphates with sulfuric acid

- Emerald green: copper salts except halides

- Weak green: Antimony, ammonium

- White-green: Zinc

- Yellow-green: Barium

- Carmine: Lithium

- Scarlet: Strontium

- Yellow-red: Calcium

- Yellow: Sodium

Synonyms and Related Terms

Brennprobe (Deut.)

Authority

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

• CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980