ABSTRACT
Flame tests are used to identify the presence of a relatively small number of metal ions in a compound. Not all metal ions give flame colors. The bead test, sometimes called the borax bead or blister test, is an analytical method used to test for the presence of certain metals. The premise of the test is that oxides of these metals produce characteristic colors when exposed to a burner flame. Some gases are hard to distinguish. For example, hydrogen, oxygen and nitrogen are all colorless and odorless. Several laboratory experiments are capable of producing relatively pure gas as an end product, and it may be useful to demonstrate the chemical identity of that gas. A common task in analytical chemistry is the identification of various ions present in a particular sample. A common method used to identify ions in a mixture is called qualitative analysis. In qualitative analysis, the ions in a mixture are separated by selective precipitation.
