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Edexcel - Chemistry Unit 2 - 4 June 2013 Watch

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    So I got 0 hours sleep on Sunday night, thought I'd go to bed relatively early for me (10pm) last night to get a nice long sleep... And I've been up since 4am -_-

    Anyone else doing some last minute cramming?
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    (Original post by Gnome :))
    So I got 0 hours sleep on Sunday night, thought I'd go to bed relatively early for me (10pm) last night to get a nice long sleep... And I've been up since 4am -_-

    Anyone else doing some last minute cramming?
    i am just wanna get over this! :/


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    (Original post by jollygood)
    Good Luck everyone !!
    thnxx u too!!


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    Exams in afternoon right?



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    (Original post by posthumus)
    Sorry I'm not sure quite what you mean? The apparatus ? Burette,conical flask & pipette ?


    SO4 has charge of -2
    therefore Cr2 has +6 charge
    +6/2 = +3
    yeah i mean what solution goes in what apparatus in the titration
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    (Original post by Matterhorn)
    Exams in afternoon right?



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    yeah
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    Hi everyone I have a couple of questions about bond angles:

    What is the bond angle of OF2?

    Are the bond angles in octahedral molecules (e.g. SF6) 90 and 180?

    Thanks!
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    (Original post by wanna_get_A*)
    i am just wanna get over this! :/


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    Not long now, just the final little push
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    (Original post by abisha)
    yeah
    Cheers (:


    Alright so for ozone how do cfc's split to form hcl? Because there are no hydrogen in cfc's? Is that hydrogen just from the surrounding air? Would any gas that has cl be a potentially damaging substance cause it splits to form cl radical?
    Thanks in advance





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    (Original post by paperclip345)
    Hi everyone I have a couple of questions about bond angles:

    What is the bond angle of OF2?

    Are the bond angles in octahedral molecules (e.g. SF6) 90 and 180?

    Thanks!
    OF2 same has H20 104.5 or 105

    octahedral has 90 and 180 as u said
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    (Original post by ramanan)
    OF2 same has H20 104.5 or 105

    octahedral has 90 and 180 as u said
    I swear I learnt from the cgp book that all the angles In an octahedral shaped molecule are 90 degrees? Was that wrong?


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    Can anyone please explain 19cii please

    Paper.
    http://www.edexcel.com/migrationdocu...e_20100121.pdf

    Mark Scheme.
    http://www.edexcel.com/migrationdocu...0_US022678.pdf

    Thanks.
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    (Original post by Matterhorn)
    I swear I learnt from the cgp book that all the angles In an octahedral shaped molecule are 90 degrees? Was that wrong?


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    The Edexcel textbook says the same thing but other websites and revision guides say it is both 90 and 180. I'm so confused
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    (Original post by paperclip345)
    The Edexcel textbook says the same thing but other websites and revision guides say it is both 90 and 180. I'm so confused
    The shape is 90 degrees so it makes sense if it's 180 degrees (straight line)
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    can someone explain me what is s1 and s2 mechanism? And the difference beween them?
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    (Original post by Matterhorn)
    Cheers (:


    Alright so for ozone how do cfc's split to form hcl? Because there are no hydrogen in cfc's? Is that hydrogen just from the surrounding air? Would any gas that has cl be a potentially damaging substance cause it splits to form cl radical?
    Thanks in advance

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    CFCs split to form chlorine free radicals. These free radicals can then react with methane to form HCl.
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    (Original post by paperclip345)
    The Edexcel textbook says the same thing but other websites and revision guides say it is both 90 and 180. I'm so confused
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    the angle B-A-B is 180 so octraheral has bothe 90 and 180
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    Why can the reaction of unsaturated vegetable oils with hydrogen and a nickel catalyst be called addition and reduction? I get the addition bit but don't know why it's reduction


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    (Original post by Matterhorn)
    Why can the reaction of unsaturated vegetable oils with hydrogen and a nickel catalyst be called addition and reduction? I get the addition bit but don't know why it's reduction


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    Reduction can be defined as:
    -gain of electrons
    -loss of oxygen
    or
    - gain of hydrogen.

    In this case, the hydrocarbon gains hydrogen, and so is reduced
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    Sf6 has to be only 90 as if u try place ur pencils like the shape of an octahedral u cannot get 180 as there is another f atom bond inbetween to form 90.
    Try check utube for some videos.
    90 as far as i know.
    hope that helps somehow
 
 
 
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