How to Conduct a Flame Test
Flame Test Lab
Your company has been contracted by Julius and Annette Benetti. They are worried about some abandoned, rusted barrels of chemicals that their daughter found while playing in the vacant lot behind their home. The barrels have begun to leak a colored liquid that flows through their property before emptying into a local sewer. The Benettis want your company to identify the compound in the liquid. Earlier work indicates that it is a dissolved metal compound. Many metals, such as lead, have been determined to be hazardous to our health. Many compounds of these metals are often soluble in water and therefore easily absorbed into the body.
Electrons in atoms jump from their ground state to excited states by absorbing energy. Eventually, these electrons fall back to their ground state, re-emitting the absorbed energy in the form of light. Because each atom has a unique structure and arrangement of electrons, each atom emits a unique spectrum of light. The characteristic light is the basis for the chemical test known as a flame test. In this test, the atoms are excited by being placed within a flame. As they re-emit the absorbed energy in the form of light, the color of the flame changes. For most metals, these changes are easily visible. However, even the presence of a tiny speck of another substance can interfere with the identification of the true color of a particular atom.
To determine what metal is contained in the barrels behind the Benettis’s house, you must first perform flame tests with a variety of standard aqueous solutions or crystals of different metal compounds. These compounds are actually classified as salts (ionic compounds containing metals and non-metals chemically bonded). Then you will perform a flame test with the unknown sample for the site to see if it matches any of the solutions or salts you used as standard. Be sure to keep your equipment very clean and perform multiple trials to check your work.
Your company has been contracted by Julius and Annette Benetti. They are worried about some abandoned, rusted barrels of chemicals that their daughter found while playing in the vacant lot behind their home. The barrels have begun to leak a colored liquid that flows through their property before emptying into a local sewer. The Benettis want your company to identify the compound in the liquid. Earlier work indicates that it is a dissolved metal compound. Many metals, such as lead, have been determined to be hazardous to our health. Many compounds of these metals are often soluble in water and therefore easily absorbed into the body.
Electrons in atoms jump from their ground state to excited states by absorbing energy. Eventually, these electrons fall back to their ground state, re-emitting the absorbed energy in the form of light. Because each atom has a unique structure and arrangement of electrons, each atom emits a unique spectrum of light. The characteristic light is the basis for the chemical test known as a flame test. In this test, the atoms are excited by being placed within a flame. As they re-emit the absorbed energy in the form of light, the color of the flame changes. For most metals, these changes are easily visible. However, even the presence of a tiny speck of another substance can interfere with the identification of the true color of a particular atom.
To determine what metal is contained in the barrels behind the Benettis’s house, you must first perform flame tests with a variety of standard aqueous solutions or crystals of different metal compounds. These compounds are actually classified as salts (ionic compounds containing metals and non-metals chemically bonded). Then you will perform a flame test with the unknown sample for the site to see if it matches any of the solutions or salts you used as standard. Be sure to keep your equipment very clean and perform multiple trials to check your work.