Flame Tests: Which Ion Causes the Color?

In this Activity, students perform simple flame tests using eleven commercially available compounds, cotton swabs, and a Bunsen burner. They then determine whether the cations or anions in each compound are responsible for the flame test colors. This Activity introduces students to flame tests in an inquiry-based manner. Most laboratory manuals state that the metal cation in an ionic compound is usually responsible for flame test colors and students verify this fact. This activity also illustrates the importance of controlling variables and making meaningful comparisons.