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    How do you approach these types of questions?
    For example the questions (grabbed from here:

    Predict the shape of the following molecules, and suggest bond angles:
    1. BeCl2
    2. SnCl2


    Any strategies or resources guys?
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    When I did AS, we were told to follow a few simple steps. State the bond angle + shape. Then we state the amount of bonding electrons + lone pairs of electrons (making sure to state that lone pairs repel slightly more than bonding pairs) and then finally to say that this shape arises from the fact that electrons repel as far as possible in space. I got an A in AS BTW (; so I'm not retarded if that's nothing to do with ur syllabus (OCR B) that definition would get full marks


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    BeCl2 I think has the same shape as water - bent/non linear, not too sure, haven't got a periodic table near me and I haven't done that stuff in ages


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    (Original post by Khanzi)
    When I did AS, we were told to follow a few simple steps. State the bond angle + shape. Then we state the amount of bonding electrons + lone pairs of electrons (making sure to state that lone pairs repel slightly more than bonding pairs) and then finally to say that this shape arises from the fact that electrons repel as far as possible in space. I got an A in AS BTW (; so I'm not retarded if that's nothing to do with ur syllabus (OCR B) that definition would get full marks


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    It's exactly the same in AQA so thanks for that
    But what I really wanted to know when I made the thread was actually drawing the shapes? Any advice?
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    Ohh sorry I didn't know u wanted that kind of hard to show u but, once u know the shapes.. Umm, for example with water... You know it's non linear. And it's three-dimensional shape is just drawn as one O molecule then add H to either side, slightly lower than a horizontal line. H-O-H then add two lone pairs around the O. If you're finding it hard to draw then I suggest get a molecule of each shape, on some flash cards, and the name of the shape. On the other side draw the shape and go over these everyday/few days. Pyramidal, non linear, trigonal planar, planar, trigonal bypryamidal, and octahedral are all the possible shapes I believe

    Making sure to use illustrate whenever the shape is in a different plane (the bond) by using the dotted lines and like triangular line comin outward, and dotted one going inward
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    (Original post by Khanzi)
    Ohh sorry I didn't know u wanted that kind of hard to show u but, once u know the shapes.. Umm, for example with water... You know it's non linear. And it's three-dimensional shape is just drawn as one O molecule then add H to either side, slightly lower than a horizontal line. H-O-H then add two lone pairs around the O. If you're finding it hard to draw then I suggest get a molecule of each shape, on some flash cards, and the name of the shape. On the other side draw the shape and go over these everyday/few days. Pyramidal, non linear, trigonal planar, planar, trigonal bypryamidal, and octahedral are all the possible shapes I believe

    Making sure to use illustrate whenever the shape is in a different plane (the bond) by using the dotted lines and like triangular line comin outward, and dotted one going inward
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    Hmm I kind of see what you're saying I guess
    Do you know how to work out bond angles?
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    (Original post by Khanzi)
    BeCl2 I think has the same shape as water - bent/non linear, not too sure, haven't got a periodic table near me and I haven't done that stuff in ages


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    BeCl2 is linear, like CO2. BeCl2 has 2 bonding pairs and 0 lone pairs. CO2 has 2 bonding regions and 0 lone pairs. Hence it is linear, with a 180o angle.

    EDIT: H2O is bent / angular. This is because H2O has 2 bonding pairs and 2 lone pairs. This gives a bond angle of 104.5o.
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    This has become easier for me now, so I thought I would update the thread.
    A useful resource shown to me by a friend is the Wikipedia document on it. Scroll down to the AXE Method and look and learn. Angles can be found by clicking on the names of the shapes.
 
 
 
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