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    Trend of Ionisation Energy across period 3: Increases

    Exception: Sulfur due to electron pair repulsion in 3p Orbital

    Element Y: Sulfur, as biggest difference in successive ionisation energies are between 6th and 7th ionisation. Normal electron configuration of Sulfur : 1S22S22P63S23P4
    Electron configuration of the ion from which the 7th ionisation energy occurs: 1S22S22P6 which means element Y must be Sulfur.

    Element with highest melting point in Period 3: Silicon due to giant covalent structure and many, strong covalent bonds which reuqire a lot of energy to break. No other element in Period 3 has a giant covalent structure.
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    Y was sulfur


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    I got 42.3% for the percentage yield. But I used 3 significant figures during the calculation.
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    (Original post by berries366)
    Yeah thats right I think
    107 is for trigonal pyramid which has 3 bonding pairs and a lone pair, SF4 has 4 bonding Pairs and a lone pair so it can't have been 107
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    (Original post by Charco63)
    107 is for trigonal pyramid which has 3 bonding pairs and a lone pair, SF4 has 4 bonding Pairs and a lone pair so it can't have been 107
    i thought it was 90
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    (Original post by Danny786)
    Sf6 is 90 and other one was 107 I think????


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    Yes, the mark scheme states anything from 106-107.5( I think) but I wrote 107.5 as the lone pair reduces the bond angle of 109.5 by 2
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    (Original post by Raizelcadres)
    Yes, the mark scheme states anything from 106-107.5( I think) but I wrote 107.5 as the lone pair reduces the bond angle of 109.5 by 2
    That's what I assumed


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    (Original post by danni1998)
    I said put both in water since methanol would dissolve as it forms H bonds with water whereas the other one (Methanethiol) or something would be insoluble?
    That's exactly what I said
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    Methanol has a higher boiling point than Methanethiol due to O-H (hydrogen bonding) being the strongest IMF as oppose to the weak VdW / dipole-dipole forces of attraction in Methanethiol, hence Methanol requires a greater input of energy to overcome its stronger IMF as oppose to Methanethiol.

    Can be separated using fractional distillation due to differing boiling points.

    Methanethiol has a smaller Mr than Selenol, and thus fewer Van der Waals forces of attraction between the molecules, which needs less energy to overcome. Hence, Selenol has a higher boiling point.
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    (Original post by Studious_Student)
    I got 42.3% for the percentage yield. But I used 3 significant figures during the calculation.
    you mean 49.3 % ?
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    (Original post by Raizelcadres)
    Yes, the mark scheme states anything from 106-107.5( I think) but I wrote 107.5 as the lone pair reduces the bond angle of 109.5 by 2
    107 is for 3 bonding pairs and 1 lone pair
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    (Original post by Emad1993)
    you mean 49.3 % ?
    how did you get that what did you divide 1.09 by
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    (Original post by Ultracrepidarian)
    i thought it was 90
    I put 89 for SF4 not sure if it I right though
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    SF4 117.5 ?
    it didnt ask for the shape of it though right?
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    (Original post by Charco63)
    107 is for trigonal pyramid which has 3 bonding pairs and a lone pair, SF4 has 4 bonding Pairs and a lone pair so it can't have been 107
    Doesn't a tetrahedral have 4 bonds and angle of 109.5 and when their is a lone pair it reduces by 2 that's how I came to 107.5. I'm not entirely sure.
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    (Original post by A2LEVELSHELPME)
    SF4 117.5 ?
    it didnt ask for the shape of it though right?
    as in it asked you to draw the shape
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    For mass spec question I put
    Similarity-same number of detections as the number of electrons doesn't change only energy.
    Difference- more peaks with lower m/z as higher energy electrons means more chance of second ionisations

    (I thought this question could be similar to the photoelectric effect questions when the say the effect of increase photon energy)
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    (Original post by MotorboatMyGoat)
    Same.

    Did you get the empirical formula as Ca3C2O8H2?
    Yeah, but I have a feeling that I wrote Cu by accident.. But I got those numbers
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    (Original post by Raizelcadres)
    Doesn't a tetrahedral have 4 bonds and angle of 109.5 and when their is a lone pair it reduces by 2 that's how I came to 107.5. I'm not entirely sure.
    was it not a square planar
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    I got the same values as you but not sure about the Mr thing
 
 
 
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