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    Can someone explain dative covalent bonding I have never really got it.
    like how do you work out if it is a dative covalent bond and which element is giving the lone pair of electrons
    can someone explain using phosphine PH3 to form PH4+.
    The specific question is to give the name of the type of bond formed when phosphine reacts with an H+ ion. Explain how it is formed
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    (Original post by allysid123)
    does anyone know why the answer to this question is A and not C?

    In which of the following series of elements is there an increase in the melting temperatures from left to right?
    A) Na Mg Al
    B) Li Na K
    C)B C N
    D) Si P S
    carbon has a much higher melting temperature than nitrogen...
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    Folks what is the ideal definition of Avogadro constant?
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    (Original post by DecentGuy)
    Folks what is the ideal definition of Avogadro constant?
    In the OCR A glossary is "The number of atoms per mole"
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    (Original post by NotoriousS)
    What's the R paper? any difference?
    its a replacement paper it is harder and I have not revised anything yet
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    (Original post by Rstlss)
    yeah?
    how are you revising for tomorrow
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    any prediction from anyone about tomrorows unit 1 paper edxcel
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    (Original post by SLRR)
    Did anyone else think the AQA EMPA was really really hard?
    Yeah, it was really hard... No idea what I put for some of my answers, just made them up on the spot... Good luck me
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    Who's on AQA here? Predictions would be appreciated
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    Could someone help me with this question please? http://gyazo.com/5b8aca37091d74dc3e68fdb651e64a05

    Answers are SO4^2 and ClO2^- but I don't understand how this corresponds with the oxidation numbers..could someone help pls?
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    If they give you a random Alkane and say what process can be used to obtain so so from it, how do you know if the answers fractional distillation or cracking? are they done on different types of hydrocarbons or is it just about what your trying to obtain
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    (Original post by Shadowfire123)
    how are you revising for tomorrow
    gonna go through all the past papers and do lots of questions
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    (Original post by Rstlss)
    gonna go through all the past papers and do lots of questions
    ohh good im gonna trying IAL jan 2014 and juen 2014 paper now
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    Can someone please help??
    Aluminium chloride has a relative molecular mass of 267 in the gas phase.Deduce the formula of the aluminium compound that has a relative molecular massof 267 (1 mark)


    5 (d) Deduce the name or formula of a compound that has the same number of atoms, thesame number of electrons and the same shape as the AlCl4− ion.
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    Hey I have a question about electron configuration. When should you use 1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 3d(10) 4s(2) 4p(6)... And when should you use 1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 4s(2) 3d(10) 4p(6)...
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    can anyone help me on jan 2014 IAl unit 1 edexcel chemistry Question 9 10 11 12 multiple cjoice wih the method please
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    (Original post by Dyl98an)
    Hey I have a question about electron configuration. When should you use 1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 3d(10) 4s(2) 4p(6)... And when should you use 1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 4s(2) 3d(10) 4p(6)...
    are you asking what element it is used for
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    (Original post by Dyl98an)
    Hey I have a question about electron configuration. When should you use 1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 3d(10) 4s(2) 4p(6)... And when should you use 1s(2) 2s(2) 2p(6) 3s(2) 3p(6) 4s(2) 3d(10) 4p(6)...
    It doesn't matter which one you use. Unless in the exam they specifically tell you to do it in the order they are filled (which would be the 4s first), they will give the marks for any order.
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    (Original post by Shadowfire123)
    are you asking what element it is used for
    No in general. Because sometimes the 3d orbital comes after. How would you know when to write 3d after 4s2
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    Hi I was just wondering - are we allowed to discuss the papers as soon as they're out? Or are the rules same as GCSE (where they have international students still haven't sat them)?
 
 
 
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