Chemistry Lab Experiment: The Flame Test Essay

Flame test: AIM: To determine which part of the salt is responsible for the characteristics in the flame. HYPOTHESIS: If we introduce a metal salt in the blue flame of the Bunsen burner, then the colour given off by the flame is due to the metal part of the salt. METHOD: (1)With a heat proof mat under the Bunsen burner, turn the gas on and light up the Bunsen burner with matches. (2)Pour enough Hydrochloric acid into a beaker. (3)Using your wire, dip it into the beaker containing Hydrochloric acid (4)Place it into the flame for a few seconds; this is the cleaning method to avoid contamination of other solutions. If the Bunsen burner flame does not change colour, then your wire is clean and you can proceed to dip it into a metal salt. (5)Dip your wire into a metal salt either the nitrate or chloride and place the wire onto the tip of the blue flame. (6)Observe the change in colour of the Bunsen burners flame and record the observations as you go. (7)As long as you clean the wire as directed in step 3-4 you can proceed into testing the other metal salts. QUESTIONS: Q1: Were there any main difference between the chloride salts and the nitrate salts? If there was please comment on what it was Yes, I had observed some difference between the colour produced from the chloride and nitrate salts present in one flame test. The strontium flame admitted both a similar orange colour, but the strontium nitrate has a much more vibrant dark orange than the strontium chloride. Q2: Suggest reasons why the experiment tested both nitrate and chloride salts? The experiment tested both nitrate and chloride salts to allow us to compare which part of salt is responsible for the colour change of the flame. Q3: Suggest why flames on gas stove burn orange-yellow when a small amount of water boils over onto them? This is due to the chemicals present in the water; such as sodium chloride, calcium ion. The orange-yellow flame admitted could also be due to the ingredients added to the water such as salt. Discussion: When the metal salt is introduced to the flame, the electrons absorb heat energy and can jump into a higher energy level. Because the electrons are now at a higher and more energetically unstable level, they fall back down to their original shell, by doing so visible light is emitted due to the energy release. Name a possible source of experiment error and suggest at least one way to reduce the effect: A possible experimental error that could have effect the result is contamination of metal salts. As directed in the steps you must clean the wire using hydrochloric acid. By doing this you are removing any traces of the previous metal salts that could alter the true colour of the flame produce by a different metal salt. By reusing the same wire at each metal salt, you could reduce the effect. Each wire will be completely free of contamination of other metal salts as it will be exposed to only one metal salt. CONCLUSION: Data collected from the flame test identified that both chloride and nitrogen tested were identical, meaning metal is responsible for the colour produced in the flame. This is evidence that strongly supports my hypothesis; therefore I accept my hypothesis on that basis.