Flame Tests
Flame Tests
12.01.2010
19.01.2010
Introduction
The normal electron configuration of atoms or ions of an element is known as the “ground state”. In this most stable energy state, all electrons are in the lowest energy levels available. When atoms or ions in the ground state are heated to high temperatures, some electrons may absorb enough energy to allow them to “jump” to higher energy levels. The element is then said to be in the “excited state”. This excited configuration is unstable, and the electrons “fall” back to their normal positions of lower energy. As the electrons return to their normal levels, the energy that was absorbed is emitted in the form of electromagnetic energy. Some of this energy may be in the form of visible light. The color of this light can be used as a means of identifying the elements involved. Such crude analyses are known as flame tests.
Only metals, with their loosely held electrons, are excited in the flame of a laboratory burner. Thus, flame tests are useful in the identification of metallic ions. Many metallic ions exhibit characteristic colors when vaporized in the burner flame. In this experiment, characteristic colors of several different metallic ions were observed, and unidentified ions were identified by means of its flame test.
Purpose
Observe the characteristic colors produced by certain metallic ions when vaporized in a flame. Identify unknown metallic ions by means of its flame test.
Hypothesis
The hypothesis for this experiment stated that the sodium ion would color the flame in yellow, the potassium ion would color it in lilac, the lithium ion would color it in carmine, the calcium ion would color it in brick red, the barium ion would color it in apple green, and the copper ion would color it in green.
Equipment
* Graduated cylinder, 10-ml * Laboratory burner * Petri dish (8) * Wire loop, spatula * Safety goggles * Lab apron or coat * Rubber gloves
Materials
12.01.2010
19.01.2010
Introduction
The normal electron configuration of atoms or ions of an element is known as the “ground state”. In this most stable energy state, all electrons are in the lowest energy levels available. When atoms or ions in the ground state are heated to high temperatures, some electrons may absorb enough energy to allow them to “jump” to higher energy levels. The element is then said to be in the “excited state”. This excited configuration is unstable, and the electrons “fall” back to their normal positions of lower energy. As the electrons return to their normal levels, the energy that was absorbed is emitted in the form of electromagnetic energy. Some of this energy may be in the form of visible light. The color of this light can be used as a means of identifying the elements involved. Such crude analyses are known as flame tests.
Only metals, with their loosely held electrons, are excited in the flame of a laboratory burner. Thus, flame tests are useful in the identification of metallic ions. Many metallic ions exhibit characteristic colors when vaporized in the burner flame. In this experiment, characteristic colors of several different metallic ions were observed, and unidentified ions were identified by means of its flame test.
Purpose
Observe the characteristic colors produced by certain metallic ions when vaporized in a flame. Identify unknown metallic ions by means of its flame test.
Hypothesis
The hypothesis for this experiment stated that the sodium ion would color the flame in yellow, the potassium ion would color it in lilac, the lithium ion would color it in carmine, the calcium ion would color it in brick red, the barium ion would color it in apple green, and the copper ion would color it in green.
Equipment
* Graduated cylinder, 10-ml * Laboratory burner * Petri dish (8) * Wire loop, spatula * Safety goggles * Lab apron or coat * Rubber gloves
Materials
Cited: Clark, Jim. “Flame Tests” Chem Guide. Helping You to Understand Chemistry. 2005. 18.01.2010. <http://www.chemguide.co.uk/inorganic/group1/flametests.html>.