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    Sorry I made a mistake
    the question is why the formula of calcium chlorate(I) is Ca(ClO)2?
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    (Original post by michmic)
    Why the formula of calcium chlorate(I) is Ca(ClO2)?
    Ca forms 2+ ions and Chlorate forms 1- ions so just do the crossover rule
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    Quick Question

    Calculate the % of avaliable chlorine in chlorine dioxide when it is reduced to chloride

    you do 35.5/35.5+2*16 * 100 then * 5
    why do you have to times it by 5 =/
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    (Original post by nukethemaly)
    I remember doing this question and I still dont get it. I've emailed my teacher about it and when she replies I'll let you know!
    could you please quote me when your teacher replies please!

    Or pm me
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    (Original post by YouKnowMyName)
    Quick Question

    Calculate the % of avaliable chlorine in chlorine dioxide when it is reduced to chloride

    you do 35.5/35.5+2*16 * 100 then * 5
    why do you have to times it by 5 =/
    is there another part to the question?

    % Cl in Cl02= 35.5/(35.5+2*16) x 100
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    How chlorate form -1?
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    Does anyone know why the June 2011 paper has the reagents/conditions for alcohol->chloroalkane as HCl and HIGH TEMP?

    Every book I have says room temp.....?
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    (Original post by Davelittle)
    Does anyone know why the June 2011 paper has the reagents/conditions for alcohol->chloroalkane as HCl and HIGH TEMP?

    Every book I have says room temp.....?
    I emailed my teacher about this and he said that most alcohols cannot undergo the reaction at room temp. In the chapter summarising the organic reactions, it says reflux to make a halogenoalkane, so high temp. is needed
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    Hey guys, i am a bit puzzled with one question from june 2011. it basically asks for the electron configuration of Iodide ions. I thought the configuration would be: 1s2 2s2 sp6 3s2 3p6 4s2 3d10 4p6 4d10 4f8 but the answer is 1s2 2s2 sp6 3s2 3p6 4s2 3d10 4p6 4d10 5s2 5p6 ... i thought the sub-shells went s,p,d,f ... if that was the case then why is there no 4f ? please help? really confused !!!
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    (Original post by Davelittle)
    Does anyone know why the June 2011 paper has the reagents/conditions for alcohol->chloroalkane as HCl and HIGH TEMP?

    Every book I have says room temp.....?
    I just got a response from my teacher about this today. If its not concentrated HCl you need to use high temp, otherwise it would be conc HCl and room temp. This makes sense to me, but what doesn't is why the mark scheme only has high temp and HCl as a possibility, surely the alternative (and the one everyone would know since its in all the text books) is room temp and conc HCl, my teacher doesn't understand how this is not in their mark scheme and so has decided to email the exam board to ask. Though unfortunately for us i doubt he will hear back by tomorrow :rolleyes:
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    June 2011 Q 3diii) when it says "...reacts with water" it means one water molecule?

    And I never get why they draw the molecules out the way they do, could someone explain?

    Posted from TSR Mobile
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    (Original post by super121)
    I emailed my teacher about this and he said that most alcohols cannot undergo the reaction at room temp. In the chapter summarising the organic reactions, it says reflux to make a halogenoalkane, so high temp. is needed
    OMG it has finally clicked for me, thank you It says in the CGP book that the room temp and conc HCl is for tertiary alcohols!!! The question in june 2011 is methanol so a primary alcohol, so yeah i'm guessing room temp isn't sufficient. Although it also says in the CGP book that the reaction conditions for a tertiary alcohol to a halogenoalkane is the only one you need to know, tut :rolleyes:
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    How can chlorate be 1-??
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    (Original post by super121)
    I emailed my teacher about this and he said that most alcohols cannot undergo the reaction at room temp. In the chapter summarising the organic reactions, it says reflux to make a halogenoalkane, so high temp. is needed
    Am I right in saying that if a high temp is used then HCl rather than conc HCl is used? As this is what the mark scheme implies
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    (Original post by michmic)
    How can chlorate be 1-??
    It just is, it forms H(ClO) so it must be -1
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    (Original post by Jlane5000)
    OMG it has finally clicked for me, thank you It says in the CGP book that the room temp and conc HCl is for tertiary alcohols!!! The question in june 2011 is methanol so a primary alcohol, so yeah i'm guessing room temp isn't sufficient. Although it also says in the CGP book that the reaction conditions for a tertiary alcohol to a halogenoalkane is the only one you need to know, tut :rolleyes:
    OMG thank you so much!

    Primary/Secondary alcohols -> Halogenoalkanes= c. HCl+ High temperatures (reflux)

    Tertiary alcohols -> Halogenoalkanes= c. HCl at room temperature (r.t.p.)

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    (Original post by Jlane5000)
    Am I right in saying that if a high temp is used then HCl rather than conc HCl is used? As this is what the mark scheme implies
    Yep
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    (Original post by super121)
    Yep
    Super, any help?

    Posted from TSR Mobile
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    Could someone tell me why June 2011 3. a) doesn't allow alcohol as a functional group?

    http://www.ocr.org.uk/Images/58494-m...urces-june.pdf

    Mark scheme
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    (Original post by nksunny)
    Hey guys, i am a bit puzzled with one question from june 2011. it basically asks for the electron configuration of Iodide ions. I thought the configuration would be: 1s2 2s2 sp6 3s2 3p6 4s2 3d10 4p6 4d10 4f8 but the answer is 1s2 2s2 sp6 3s2 3p6 4s2 3d10 4p6 4d10 5s2 5p6 ... i thought the sub-shells went s,p,d,f ... if that was the case then why is there no 4f ? please help? really confused !!!
    Where are you getting the 4f from? Iodine is nowhere near the f block.
 
 
 
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