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7: Flame Test And Identification Of Unknown

  • Page ID
    506175
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    PURPOSE

    The purpose of this experiment is to: 

    • To perform flame tests on solutions containing various elements and examine the colors produced.

    • Record observations from several double displacement reactions.

    • Identify an unknown based on the results of flame tests and double displacement reactions. 

    INTRODUCTION

    In the lecture, you learned about two models of atomic structure: the Rutherford and Bohr models. The Rutherford model states that most of the atom’s mass comes from the nucleus, which is positively charged and resides at the center of the atom. In this model, electrons randomly orbit the nucleus in circular paths. The Bohr model explains that protons and neutrons are inside the atom’s nucleus. Electrons exist at specific energy levels outside the nucleus.

    When solutions containing various elements are heated, electrons transition from a lower to a higher energy level. Electrons eventually return to their original energy levels, and when they do, they often emit energy as visible light. Evidence for the Bohr model is observed in the light emitted as materials containing certain elements are heated. Because electrons exist at specific energy levels and are not randomly placed outside the nucleus, each component has its characteristic pattern of energy levels, and, as a result, emits its characteristic pattern of light.

    In this experiment, you will run flame tests on several known solutions and an unknown. You will react to these same chemical solutions with various reagents and record the observations of the resulting double displacement reactions. Based on these results, you can identify the components of an unknown solution.

        


    This page titled 7: Flame Test And Identification Of Unknown is shared under a CC BY license and was authored, remixed, and/or curated by Saadia Khan.