This page explains how to perform a flame test because that a selection of metal ions, and briefly discusses exactly how the flame color arises. Fire tests are provided to recognize the presence of a reasonably small variety of metal ion in a compound. Not all metal ions offer flame colors. For team 1 compounds, fire tests are usually by much the easiest means of identifying which steel you have got. For other metals, there space usually various other easy methods that are much more reliable - however the flame test can give a beneficial hint regarding where to look.

You are watching: How can you identify an unknown element using a flame test

*
Figure (PageIndex1): colored flames indigenous strontium, cesium, sodium and also lithium (from left to right). Snapshot courtesy the the Claire Murray and also Annabelle Baker indigenous the Diamond irradiate Source. Confirm the colors v the facets on Table (PageIndex1).

Practical Details in moving out fire Tests

Clean a platinum or nichrome (a nickel-chromium alloy) cable by dipping it into focused hydrochloric acid and then holding the in a hot Bunsen flame. Repeat this till the cable produces no color in the flame. Once the wire is clean, moisten that again in the acid and then dip it into a tiny amount that the solid come be experiment so that some sticks come the wire. Location the wire earlier in the flame. If the flame shade is weak, it is often valuable to emboldened the wire ago in the acid and also put it earlier into the flame together if clean it. This should develop a really short however intense flash of color.

There will, in fact, constantly be a map of orange in the flame if you usage nichrome. Platinum is much far better to use however is much, much an ext expensive. If you have a an especially dirty little bit of nichrome wire, you can just chop the finish off. You perform not execute that with platinum! Dilute hydrochloric acid can be used instead of focused acid for safety reasons, however does not constantly give such extreme flame colors.


The color in Table (PageIndex1) are simply a guide. Virtually everybody sees and also describes colors differently. I have, because that example, supplied the word "red" number of times to define colors that can be quite different from every other. Other world use words prefer "carmine" or "crimson" or "scarlet", yet not everyone knows the differences in between these native - an especially if their an initial language is not English.

See more: What Is 45 In Decimal Form, What Is 45/100 As A Decimal

Table (PageIndex1): fire colors the common aspects 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 with white flashes)
Lead gray-white

What execute you perform if you have a red flame color for one unknown compound and do not understand which the the various reds it is? acquire samples of well-known lithium, strontium (etc) compounds and also repeat the flame test, comparing the colors created by among the recognized compounds and the unknown link side through side until you have actually a great match.