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    (Original post by z!D4N)
    one question

    in the exam, should i use temporary instantaneous induced dipole-diplole or just temporary dipoles?
    I would prefere Instentaneous dipole induced dipole! :rolleyes:
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    Induced dipole, or dispersion forces...
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    (Original post by daydream)
    uimm sorry so back to the electrophiles and neuclophiles.. someone earlier methioned that electrophile have 6 electrons on outer shell and neucleophile has 8? what about OH- it only has 7 but it's neucleophile
    Ok .. Diffenitions:
    Electrophile - Is an electron-Dificient species which has the ability to Accept a lone pair/s of electron[to form dative Covalent bond].And so, its attracted to regions of negative charge.
    Nucleophile - Is an Electron-rich species which has the ability to Donate a Lone pair/s of electron[to form dative Covalent bond].And so, its attracted to regions of Positive charge.

    nueclophiles-electrophiles doesnt have a constant number of lone pairs as u stated.it Varies between different species.
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    ok i get it now
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    (Original post by daydream)
    ok i get it now
    Great !
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    does anybody find chemistry easier than physics at AS?
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    (Original post by z!D4N)
    does anybody find chemistry easier than physics at AS?
    I think I do. Although, I'll have to wait 'till results day to find out
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    Question:

    If a substance give off Monoatomic vapour when it boils, doesnt that mean that all the bonds are broken including inter & intra molecular forces?
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    (Original post by KOH)
    Question:

    If a substance give off Monoatomic vapour when it boils, doesnt that mean that all the bonds are broken including inter & intra molecular forces?
    Gasses have no intermolecular bonds, so to melt AND boil a solid you break ALL the intermolecular bonds (bonds between molecules).

    What do you mean by "monoatomic"? Like inert gasses?
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    (Original post by mik1a)
    Gasses have no bonds, so to melt AND boil a solid you break ALL the bonds, inter and intra.

    What do you mean by "monoatomic"? Like inert gasses?

    e.g when you melt P4 the gas consistes of P only no P4 right?
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    O=C=O carbon dioxide dipoles cancel out making it non polar but why do O=S=O (shaped like water) sulphur dioxide dipoles not cancel out? I thought they just had to be symetrical?
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    (Original post by mik1a)
    Gasses have no bonds, so to melt AND boil a solid you break ALL the bonds, inter and intra.

    What do you mean by "monoatomic"? Like inert gasses?
    r u sure gases hav no bonds?
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    (Original post by KOH)
    e.g when you melt P4 the gas consistes of P only no P4 right?
    Ok. Yeah since the P(g) atoms have too much kinetic energy to form a giant covelant network, they do no bonding. In gasses like this you break every sort of bond - there are no forces (practically) between atoms.

    Although with gasses like Cl(2) and CO(2) there are covelant bonds, there are no intermolecular forces until the temperature comes close to melting point, where some molecules have enough "lack" of energy to form molecules.

    (Original post by z!D4N)
    r u sure gases hav no bonds?
    No. I just realised that was garbage! Of course H2 and Cl2 have bonds... lol what a fool. I'll edit it now.
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    (Original post by Ramaya)
    O=C=O carbon dioxide dipoles cancel out making it non polar but why do O=S=O (shaped like water) sulphur dioxide dipoles not cancel out? I thought they just had to be symetrical?
    Could it be to do with elctronegativity? (I'm just guessing here)
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    (Original post by LS.)
    Could it be to do with elctronegativity? (I'm just guessing here)
    Hmm its under that section in the book - it says that SO2 has a -ve and a +ve end but CO2 does not. I am wondering if its to do with the shape perhaps.
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    (Original post by Ramaya)
    O=C=O carbon dioxide dipoles cancel out making it non polar but why do O=S=O (shaped like water) sulphur dioxide dipoles not cancel out? I thought they just had to be symetrical?
    Because SO2 is not linear - the sulphur has a free d orbital, so in SO2, is forms double covelant bonds with oxygen and still has one lone pair, making it v-shaped. THerefore the polarities don't cancel out and the molecule has a dipole.
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    (Original post by mik1a)
    Because SO2 is not linear - the sulphur has a free d orbital, so in SO2, is forms double covelant bonds with oxygen and still has one lone pair, making it v-shaped. THerefore the polarities don't cancel out and the molecule has a dipole.
    Oh right! I understand it now. Thankyou very much
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    What the hell!
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    (Original post by KOH)
    Question:

    If a substance give off Monoatomic vapour when it boils, doesnt that mean that all the bonds are broken including inter & intra molecular forces?
    It depends on what do u mean by a substance:
    If it was an element :
    Inter = yea becuz atoms are far apart from each other .. and they dont exert forces on each others
    Intra= yea for all elements except Noble gases.. Becuz Noble gases are in the Monoatomic phase naturally ..
    If it was a Compound:
    inter = ofcourse same as above .. becuz molecules dont exert forces between each others
    intra =it depends on the compound of it is made up of molecules then yea .. intra are broken
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    ANyone doing 3b edexcel chem exam on thursday???
    if so, how r u revising, its a retake and when i took it the 1st time round we werent evn told we had it! heh
 
 
 

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