There are several different tests to detect and identify the ions in compounds. It is important that the test for any ion is unique. The results of a test must let you determine which ion is present, rather than being uncertain about which ion it is.
Different metal ions produce different flame colours when they are heated strongly. This is the basis of flame tests. To carry out a flame test:
The table shows the flame test colours for six common metal ions.
|Ion present||Flame test colour|
A sample of an ionic compound produces an orange-red flame test colour. Identify the metal ion present.
The metal ion is calcium, Ca2+.