Flame+tests

=Flame Tests= Flame tests are a method of identifying an unknown salt by placing a sample in a flame and observing the color. Different ions produce different flames according to their unique identity on the color spectrum. The flame test can be performed by using a piece of uncontaminated nichrome wire dipped in a concentrated hydrochloric acid and putting a solid of which you would wish to test onto the wire. This wire is to be held over a hot Bunsen burner flame until some visible change occurs. This reaction is the result of a certain compound being excited by the addition of heat, therefore causing the metal ions to emit a light. This technique is used mainly be pyrotechnics to produce the many colors we see in fireworks displays.

The following lists ions and their identifying color: Lithium (Li 1+): Red Strontium (Sr 2+): Scarlet/Crimson Calcium (Ca 1+): Orange Sodium (Na 1+): Yellow Zinc (Zn 2+): White/White-Green Copper (Cu 2+): Emerald Green (shown below) Thallium (Tl 1+, 3+): Emerald Green Antimony (Sb 3+, 5+): Light Green Barium (Ba 2+): Yellow-Green Lead (Pb 2+, 4+): Blue Bismuth (Bi 3+, 5+): Blue Potassium (K 1+): Violet/Red-Violet Rubidium (Rb 1+): Red-Violet Cesium (Cs 1+): Red-Violet Selenium (Se 2-): Blue Arsenic (As 3-): Light Blue Phosphate (PO4 3-): Blue-Green

Flame Produced by a Copper Sample

Sources http://chemistry.about.com/library/weekly/aa110401a.htm [|www.amazingrust.com/Experiments/how_to/Flame_Test.htm]

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