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    good luck! u;ll do fine...
    isn the paper on thurs though?
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    Why doesn't Be react with H2O?
    Is it b/c it has a very high ionisation energy?
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    I've come across this in the syllabus, I have no idea what it means, any help?

    - use given data about absorbtion ranges to make predictions about the effect of substances on radiation
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    (Original post by LS.)
    - use given data about absorbtion ranges to make predictions about the effect of substances on radiation
    This sounds like it is from the A2 sylibus when you have to do spectromitry stuff. What sylibus is it from?
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    OCR (Salters) - it's definately on the AS syllabus
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    (Original post by LS.)
    I've come across this in the syllabus, I have no idea what it means, any help?

    - use given data about absorbtion ranges to make predictions about the effect of substances on radiation
    I think it means that you should be able to recognice when the absorbtion range is within the visible spectrum - so the substance will absorb light of that wavelength (and appear the "opposite" colour).
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    (Original post by calumc)
    I think it means that you should be able to recognice when the absorbtion range is within the visible spectrum - so the substance will absorb light of that wavelength (and appear the "opposite" colour).
    Hm, I think I get it. It's together with the stuff about E=hv and the electronic, vibrational, rotational and translational energy stuff - which I get. Hopefully it's just an extraction on that.
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    Hey, I'm doing Edexcel chem (not nuffield) on Thursday. For somereason I'm ok with Unit 1/2 but always seem to stuff up on the 3B (written prac) paper despite most of the answers being common sense. What sort of experiments will we need to design on the last questions? Looking at past questions the only ones I've come across are rates of reaction, working out relative atomic mass and finding out conc. Any others that could crop up?

    Ta
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    you can find out on the specifications
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    (Original post by Heidi)
    Why doesn't Be react with H2O?
    Is it b/c it has a very high ionisation energy?
    Yea ..
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    (Original post by Dust)
    good luck! u;ll do fine...
    isn the paper on thurs though?
    Ohh No .. i am doin the CIE = Camvridge international examinations...
    Well i should say i DID !!HURRAY!! i feel soo happy and soo sad for u guyz
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    i had some kinda tough questions
    -2 uses of ammonia ??!
    is used to produce Nitric acid and Fertilazer the same point .. cuz i wrote them :P

    -Major use of esters other than food addiditives/perfumes??
    I wrote paints .. is that right ??!! :confused:

    -2 Organic Substances that replaces Halgenoalkanes when they are used as refrigerants ,aerosol propellent.
    i wrote Alkenes and Alkynes .. [Big Wild Guess ]

    -write the equation for the netralization of Ammonia by Sulphuric acid:
    2NH3 + H2SO4 ---> [NH4]2.SO4 [Any chances of gettin it right ?? ]

    - S3P4 + O2 -----> ??? what does it Gives u ??
    the question is continued by = the products when added to water they for acids.. write equations for this.
    i wrote S3P4 + 8O2 ---> 3SO2 + 4PO3
    then i wrote .. So2 + H2O ----> H2SO3
    PO3 + H2O ----> H2PO4 right wrong ??!!

    THnx .. and Good Luck
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    Explain why methane does not react with reagents such as nucleophiles or electrophiles. [2 marks- from OCR Chains and Rings paper June 2003]
    im guessing that it's because it's not polar? but im unsure
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    (Original post by hihihihi)
    Explain why methane does not react with reagents such as nucleophiles or electrophiles. [2 marks- from OCR Chains and Rings paper June 2003]
    im guessing that it's because it's not polar? but im unsure
    Yup.. it doesnt have a charge which attract a neuclophile-electrophile .. thats one reason why its quite stable .. the other one becuz it doesnt have a double bond
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    Why is the Haber process so important for mankind?

    [4 marks]
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    (Original post by hihihihi)
    Why is the Haber process so important for mankind?

    [4 marks]
    Well becuz it prodices ammonia which can be used in the formation of fertilizers .. which helps in irragation .. and production of Good ,,Nutritious food .. which Helps us to survive...
    Also used to make Nitric acid ----> TNT.. which is important for Mining ..
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    (Original post by hihihihi)
    Why is the Haber process so important for mankind?

    [4 marks]
    ammonia can be used to react with nitric acid to make fertilisers. and its also used for making nitric acid.
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    I Hope u guyz answer questions i Posted
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    need help
    titration indicator
    methyl-orange: red - > orange-yellow test for acid
    phenolphthalein: colorless - > pink test for alkalin
    right?
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    Hi can anyone tell the purification of Bauxite with Naoh .

    Pls help
 
 
 

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