This page defines how to execute a flame test because that a range of steel ions, and briefly discusses how the flame color arises. Fire tests are used to determine the visibility of a reasonably small number of metal ion in a compound. Not all metal ions provide flame colors. For team 1 compounds, flame tests room usually by far the easiest method of identifying which metal you have got. For other metals, there space usually various other easy approaches that are an ext reliable - however the flame test can give a useful hint regarding where come look.

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Figure \(\PageIndex1\): fancy flames indigenous strontium, cesium, sodium and lithium (from left to right). Photo courtesy that the Claire Murray and Annabelle Baker indigenous the Diamond light Source. Check the colors v the elements on Table \(\PageIndex1\).

Practical Details in transferring out flame Tests

Clean a platinum or nichrome (a nickel-chromium alloy) wire by dipping that into focused hydrochloric acid and then holding that in a hot Bunsen flame. Repeat this till the cable produces no shade in the flame. Once the cable is clean, moisten that again in the acid and also then dive it into a tiny amount that the solid come be tested so that some sticks to the wire. Ar the wire earlier in the flame. If the flame color is weak, that is often useful to dive the wire earlier in the acid and also put it earlier into the flame together if cleaning it. This should create a really short yet intense speed of color.

There will, in fact, always be a map of orange in the fire if you use nichrome. Platinum is much far better to use yet is much, much much more expensive. If you have actually a specifically dirty little bit of nichrome wire, you can just chop the finish off. You perform not do that v platinum! Dilute hydrochloric acid deserve to be used instead of concentrated acid for safety reasons, but does not always give such intense flame colors.


The colors in Table \(\PageIndex1\) are just a guide. Nearly everybody sees and also describes color differently. I have, for example, used the word "red" several times to explain colors that have the right to be quite various from each other. Other world use words like "carmine" or "crimson" or "scarlet", but not everyone knows the differences between these words - particularly if their an initial language is no English.

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Table \(\PageIndex1\): fire colors the common facets Elementflame color
Lithium red
Sodium strong, persistent orange
Potassium lilac (pink)
Rubidium red (red-violet)
Cesium blue/violet (see below)
Calcium orange-red
Strontium red
Barium pale green
Copper blue-green (often v white flashes)
Lead gray-white

What do you do if you have a red flame shade for one unknown compound and do not know which the the assorted reds the is? get samples of known lithium, strontium (etc) compounds and repeat the flame test, to compare the colors developed by one of the well-known compounds and the unknown link side through side till you have actually a good match.