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    Pretty sure the iodine value was ~80.6g
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    (Original post by ToxicPhantom007)
    The number of moles you got is right. Though they asked that thses moles are in 0.2 g of oil so in 100 g of oil we had to multiply moles by 500 and the moles came were 0.45 something
    0.45 x 2(126.9)= 114.8 g
    80 is wrong
    Wasn't the moles 0.3 or something tho?
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    (Original post by Hdb)
    Pretty sure the iodine value was ~80.6g
    I reckon so
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    (Original post by RUNSran)
    Oh I get it .. do you think i will the marks that follows if i carry my error forward?
    ECF would definitely apply so you've lost maybe 1/2 marks max on that calculation.
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    I got 107
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    (Original post by Crespo0008)
    I reckon so
    Everyone apart from 1 person I know got that value lol! It was more of a unit 4 calculation haha
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    What did everyone get for the very last question about the sample and iodine-would it increase, decrease or neither?
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    (Original post by mayaham12)
    What did everyone get for the very last question about the sample and iodine-would it increase, decrease or neither?
    Increased titre, lower iodine value.
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    How did people explain what was going in step 1 and 2 of the thermal decomposition of Mg(NO3)2
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    (Original post by corpeal)
    How did people explain what was going in step 1 and 2 of the thermal decomposition of Mg(NO3)2
    Thought water would come out in step 1, then it would turn to steam in step 2 after enough heating.
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    (Original post by RUNSran)
    yeah i got something similar - dont know how people got 80 something. What was the moles of s203 that reacted in the blank titration?
    0.004 moles? i don't remember exactly
    what did you get? ^_^
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    (Original post by scrlk)
    Increased titre, lower iodine value.
    same
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    Does anybody know the value of the concentration calculation in the multiple choice?
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    i got 0.3725 or something like that i cant remember fully
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    (Original post by beanigger)
    i got 0.3725 or something like that i cant remember fully
    0.001-0.000365=0.000635, 0.000635x500=0.3175
    126.9x2x0.3175=80.58g
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    (Original post by Hdb)
    Does anybody know the value of the concentration calculation in the multiple choice?

    0.33
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    Hey I have 3 questions about section A
    What was the 1st answer? I put C (3)
    What was the conc of na2s04? I guessed and put 0.5
    What was organic molecule using wave number And? I out the aldehyde one
    Ty guys
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    (Original post by corpeal)
    How did people explain what was going in step 1 and 2 of the thermal decomposition of Mg(NO3)2
    Step 1: I assumed that some of the Mg(OH)2 had precipitated out of the solution and that upon heating its solubility increases and so dissolves back into it.

    Step 2: Water was evaporating and CaO was being formed via thermal decomposition
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    (Original post by Kaka121)
    Hey I have 3 questions about section A
    What was the 1st answer? I put C (3)
    What was the conc of na2s04? I guessed and put 0.5
    What was organic molecule using wave number And? I out the aldehyde one
    Ty guys
    Yeah first one I put C too,
    I put 0.33 for the concentration.
    And I take it you mean the IR spectra, where I also put the aldehyde.
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    (Original post by JoeyTr)
    Yeah first one I put C too,
    I put 0.33 for the concentration.
    And I take it you mean the IR spectra, where I also put the aldehyde.
    Ohh ok are you sure C was right?! And how did you get 0.33?
    Lastly did you also get 0.4 for uncertainty? I think I got 19/20 in section A hopefully
 
 
 
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