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    C-Cl is stronger than C-Br because Cl is smaller and the bonding electrons can get closer to the nucleus. (It has nothing so to with polarity)

    However Br2 has a higher boiling point than Cl2 because it is larger and has more electrons so stronger instantaneous dipole-induced dipole bonds which require more energy to break.

    Regarding -OH groups and polymer solubility, one OH on the monomer is only slightly soluble but all OH groups means the polymer is more attracted to its other OH groups than the H2O so it is not soluble.
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    (Original post by Davelittle)
    C-Cl is stronger than C-Br because Cl is smaller and the bonding electrons can get closer to the nucleus. (It has nothing so to with polarity)

    However Br2 has a higher boiling point than Cl2 because it is larger and has more electrons so stronger instantaneous dipole-induced dipole bonds which require more energy to break.

    Regarding -OH groups and polymer solubility, one OH on the monomer is only slightly soluble but all OH groups means the polymer is more attracted to its other OH groups than the H2O so it is not soluble.
    What about bond polarity?

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    (Original post by Branny101)
    What about bond polarity?

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    bond polarity is related to electronegativity, the more electronegative it is, the more polarity it has.
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    (Original post by Branny101)
    What about bond polarity?

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    Bond polarity doesn't affect bond strength (there was a question in Jan 2013 on this)
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    (Original post by Davelittle)
    Bond polarity doesn't affect bond strength (there was a question in Jan 2013 on this)
    So what effects bond strength, it all confuses me im sure polarity plays a part

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    Afternoon exam right?
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    yes afternoon exam
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    (Original post by JoshThomas)
    So what effects bond strength, it all confuses me im sure polarity plays a part

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    Bond reactivity in this term depends on how close the outer shell electron is to the nucleus; the outer shell electron in Bromine is further away than Chlorine, as it's a larger atom; thus there's less nuclear charge, thus less energy is required for Bromine to lose its electron and react.

    Bond polarity plays a very small role in the case of halogenoalkanes. Bond reactivity explains why the rate of hydrolysis is faster for bromoalkanes than chloroalkanes, as simply the C-Br is weaker than the C-Cl bond, so it'll take less time to break the C-Br bond and hence react quicker.

    There was a question on this in the June 2007 legacy paper, and recently in the Jan 2013 paper. Try doing them, it'll help

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    How do we explain the difference in silicon dioxide and carbon dioxide in terms of boiling and melting points?

    Also in the Jan 2010 paper is asks you to give the name and full structure of another alkene monomer that is reacted to but-2-ene to get co-polymer A
    It says the answers is propene, but I don't understand why?

    Also last question, What is the instantaneous-induced forces and van der waals? I understand some of it but not properly
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    (Original post by Whostolemycookie)
    How do we explain the difference in silicon dioxide and carbon dioxide in terms of boiling and melting points?

    Also in the Jan 2010 paper is asks you to give the name and full structure of another alkene monomer that is reacted to but-2-ene to get co-polymer A
    It says the answers is propene, but I don't understand why?
    SiO2 has a giant lattice structure with covalent bonding. CO2, O=C=O, has a simple molecular structure with covalent bonding. Bonds in SiO2 are stronger than weak intermolecular bonds in CO2.
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    (Original post by krisshP)
    SiO2 has a giant lattice structure with covalent bonding. CO2, O=C=O, has a simple molecular structure with covalent bonding. Bonds in SiO2 are stronger than weak intermolecular bonds in CO2.
    No I meant in terms of boiling and melting points not bonds and structure
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    (Original post by Whostolemycookie)
    No I meant in terms of boiling and melting points not bonds and structure
    That ^ is the explanation for why SiO2 his a higher boiling an higher melting point than CO2.
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    (Original post by Whostolemycookie)
    No I meant in terms of boiling and melting points not bonds and structure
    The bonding and structure is what makes the boiling points differ,

    Co2 has weak inter molecular forces so less energy is required to break bonds, this means the melting/ boiling point is much lower whereas Si02 has strong covalent bonds which require a lot of energy so has a higher temperature!
    Remember Sio2 does NOT have inter molecular forces
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    (Original post by krisshP)
    That ^ is the explanation for why SiO2 his a higher boiling an higher melting point than CO2.

    (Original post by tigerz)
    The bonding and structure is what makes the boiling points differ,

    Co2 has weak inter molecular forces so less energy is required to break bonds, this means the melting/ boiling point is much lower whereas Si02 has strong covalent bonds which require a lot of energy so has a higher temperature!
    Remember Sio2 does NOT have inter molecular forces
    Ok I understand thank you
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    really wish i'd gone to bed earlier, ugh
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    Do you think there will be any ozone questions?
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    I pretty sure they'll have a OZone question

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    (Original post by TheNote)
    I pretty sure they'll have a OZone question

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    Yeah but I mean like the detailed ones e.g. how chlorine radicals break up troposphere
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    Urgent question


    How does N2O control ozone abundance in stratosphere?
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    What question could they ask about green chemistry?
    I really haven't revised it tbh
 
 
 
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