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Grade 9 Science Experiment Help!

  1. Mar 9, 2009 #1
    1. The problem statement, all variables and given/known data

    I didn't get time to finish the experiment, and didn't get much done, so my teacher told me to copy someone elses work and varify if it was correct, but i dont know how. here is the info i have:

    Qualitative Analysis of Unknown Gasses

    In this experiment, you will be using known properties of 3 gases in order to ultimately identify an unkown gas.

    Procedure (the teacher gave us this):

    1. using a clean test tube, fill the test tube approximately 1/3 full with hydrochloric acid
    2. with your Bunsen burner lit and ready, place a 2 cm piece of Mg ribbon into the test tube with the acid stopper immediately
    3. keep your thumb on the stopper to prevent any gas from escaping.
    4. Preform the flame test to identify the gas either hydrogen or oxygen.
    5. Repeat steps 1-4 using hydrogen peroxide and manganese dioxide
    6. repeat steps 1-4 using zinc metal and hydroclhloric acid.

    2. Relevant equations

    given in # 1

    3. The attempt at a solution

    Okay. So I got that Mg in Hydrocloric acid is hydrogen because it made a poping noise. But I couldn’t figure out the others on time, (I only had a half hour) so this is what my friend got:

    Unknown Gas : Magnesium
    Observation: Loud pop
    Hydrogen or oxygen: hydrogen

    Unknown Gas: Zinc
    Observation: Loud pop
    Hydrogen or oxygen: Hydrogen

    Unknown Gas: Magnesium + Peroxide
    Observation: Splint + Glowed Bright
    Hydrogen or oxygen: Oxygen.
  2. jcsd
  3. Mar 9, 2009 #2


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    Your friend sounds pretty smart...
  4. Mar 9, 2009 #3
    Thanks, i hope what you mean is i/they did it right!! :D
  5. Mar 9, 2009 #4


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    Those seem correct to me. For completeness, however, you should be able to describe why hydrogen will give you a loud pop when you perform the flame test and why oxygen causes the splint to glow.
  6. Mar 9, 2009 #5
    Squeaky pop test = win
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