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Thread: Chemistry final. In need of assistance.

  1. #1 Chemistry final. In need of assistance. 
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    Let me begin by introducing myself,

    Well, I will refer to myself as Burbuat. I have, for the past 4 days, tried to identify an unknown substance provided for me by my teacher. We have 8 days to identify this unknown substance, but I am afraid I will not be able to correctly identify this unknown substance without proper assistance.
    We have run some basic tests to try to hint at what the substance may be, but I will need your help in narrowing it down.

    We have done a flame test, and the flame burned at an orange/yellow flame, although my group swears they see a tiny hint of purple now and then, but I believe that is just paranoia sinking in form our approaching deadline.

    We have also done a percipitate test, and we had results that hinted at the fact that our substance has Chlorine in it because the test tube was filled with clumps of a white flaky material, and the water became hazy. We conducted this lab with Silver Nitrate, we placed our unknown substance in a test tube, and we put a few drops of silver Nitrate into it. And the above percipitate formed.

    In additon to that, we did a conductivity test. Which was a test in which we hooked up copper wiring to a battery, and placed these positively and negatively charged wires into our unknown substance, which we poured onto a watchglass. After a while, green colored clumps began to form in the pool of our unknown substance. And the water took on a slightly gray tint to it. We also clipped a light bulb onto the copper wiring to see if the compound we had was covalent or ionic, the lightbulb didn't light, so we assumed that the compound is either a very weak Ionic bond or a Covalent bond. But remember, our substance has been significantly diluted, it is about 90 percent water and 10 percent substance, and I believe that is why the lightbulb did not light.

    Finally, we conducted a PH test and the PH of our substance was 7.

    Now, our unknown substance is one from this list...

    Sodium Borate.
    Potassium chloride.
    Calcium chloride.
    Or Sodium chloride

    I humbly ask you for assistance... and contribution would be greatly appreciated.

    -Burbuat


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  3. #2  
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    From what you know you can already eliminate one or more of the substances. Which ones can you eliminate?


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  4. #3  
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    Quote Originally Posted by cypress
    From what you know you can already eliminate one or more of the substances. Which ones can you eliminate?
    Obviously, the Borate can be eliminated, I just provided all the answers... just in case one of you intellectuals chose to plead,"Green? Clumps? Well, that is quite obviously a Borate."
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  5. #4  
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    What about the sodium chloride? How conductive is 10% NaCl?
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    What about the sodium chloride? How conductive is 10% NaCl?
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  7. #6  
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    I'm tempted to say Sodium Chloride, as far as I know it has a ph of 7


    Do you have the concentrations of the viable answers? any with strong concentrations would probably disaccosiate and cause the ph to differ from the neutral of the medium
    It's not how many questions you ask, but the answers you get - Booms

    This is the Acadamy of Science! we don't need to 'prove' anything!
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  8. #7  
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    Hi there

    It's got to be sodium chloride by the test results..
    Sodium compounds glow yellow in a flame and when you passed electricity through a solution the green clumps formed would be copper chloride (at the anode). For this to occur the substance must be ionic rather than covalent...
    That's my thoughts for what it's worth
    All the best from the North

    Ray
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