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    Does the entropy become more positive when a liquid changes state to a gas?
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    (Original post by OFoster)
    Does the entropy become more positive when a liquid changes state to a gas?
    yes, because disorder increases
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    (Original post by OFoster)
    Does the entropy become more positive when a liquid changes state to a gas?
    Yes as there's an increase in disorder
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    Can anyone distinguish between electronegativity, polarising power, trends in lattice enthalpy and when you talk about size to charge - they're all very similar!
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    (Original post by Anshul91)
    so what type of molecules are like that which have 'X'Cl2 do yo u know?
    Yes all the group 2 ones So we'll both remember to multiply them by 2 if it comes up tomorrow haha
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    (Original post by megsy14)
    Could someone kindly link me the jan 13 mark scheme? it would be much appreciated
    here
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  1. File Type: pdf Jan13 CHEM5.pdf (152.5 KB, 63 views)
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    does anyone have a document or something that list the observation for period 3 elements
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    (Original post by Anshul91)
    no if they give you the lattive formation rather than the lattice disociation then you use:


    enthalpy of solution = - lattive formation + sum of enthalpy of hydration.
    Ohh okie doke. So confusing. I hope this doesn't come up tomorrow since it already came in the Jan paper
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    Ligand- an atom, ion or molecule which can donate a pair of electrons to central metal ion.

    Co-ordinate bond- when a pair of electrons in covalent bond come from one atom.

    Complex ion- central metal ion which is surrounded by one or more ligands by dative covalent bonds.

    Coordination number- the number of electron pairs donated by ligands.

    Are these definitions correct or is there anything else i need to add to it?
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    Could someone please help with question 7(b)(ii) for Jan 2011 paper. I odn't understand how it has been done.

    http://a-levelchemistry.co.uk/AQA%20...W-QP-Jan11.pdf
    http://filestore.aqa.org.uk/subjects...W-MS-JAN11.PDF
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    Fe(h20)3(oh)3 , Cr(h20)3(oh)3 , Cu(h20)3(oh)3 ,
    Can anyone tell me the colours for these?


    Posted from TSR Mobile
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    (Original post by hawraaj313)
    Ligand- an atom, ion or molecule which can donate a pair of electrons to central metal ion.

    Co-ordinate bond- when a pair of electrons in covalent bond come from one atom.

    Complex ion- central metal ion which is surrounded by one or more ligands by dative covalent bonds.

    Coordination number- the number of electron pairs donated by ligands.

    Are these definitions correct or is there anything else i need to add to it?
    Coordination number refers to the number of coordinate bonds formed with the central metal ion.
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    Please could someone explain the equation for reaction 2 in this paper. Qs 8a http://filestore.aqa.org.uk/subjects...5-QP-JUN12.PDF
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    (Original post by Learner_108)
    Fe(h20)3(oh)3 , Cr(h20)3(oh)3 , Cu(h20)3(oh)3 ,
    Can anyone tell me the colours for these?


    Posted from TSR Mobile
    Iron one is brown ppt
    Cr one is pale green ppt
    Cu one is blue-green ppt (Cu(h2o)4(oh)2)
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    (Original post by flyylikejetz)
    In born haber cycles i thought if you wanted to find ΔHf the equation was ΔHa + ΔIE(Ca) + Δea + ΔHld = ΔHf
    but on June 10, question 1 (b) (iii) you take away the ΔHlatticedissociation from the rest :confused: can anyone explain please ?
    anyone ... ?
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    (Original post by Learner_108)
    Fe(h20)3(oh)3 , Cr(h20)3(oh)3 , Cu(h20)3(oh)3 ,
    Can anyone tell me the colours for these?


    Posted from TSR Mobile
    Fe(h20)3(oh)3 is a brown ppt
    Cr(h20)3(oh)3 is a green ppt
    Cu(h20)3(oh)3 think you should have wrote Cu(H20)4 (OH)2 as its a 2+ ions and that is a blue ppt
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    (Original post by starfish232)
    Coordination number refers to the number of coordinate bonds formed with the central metal ion.
    thanks, it was on the mark scheme thats why
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    on the jan 2011 paper for 7c, how do they get the balanced equation between the hydrogen peroxide and manganate ions? is there a quick way of working it out or is it just trial and error?
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    How did you guys find Jan13?
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    (Original post by flyylikejetz)
    anyone ... ?
    Just follow the the cycle. It should be the sum of all the other enthalpies
 
 
 
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