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    Hi,

    The question I’m working on is…

    i) use electron pair repulsion theory to deduce the shape of BF3<---NH3
    ii) suggest the shape of the molecule if B is the central atom
    iii) suggest the shape of the molecule if N is the central atom

    On an older post I was looking at for the same question they concluded that BF3 was trigonal planar but I don't understand how BF3 is trigonal planar, surely it has 4 groups of electrons around it, one of which being the lone pair which is a dative bond from the nitrogen?

    Wouldn't this mean it's tetrahedral because ithas 4 groups and then because one of the groups is a lone pair the moleculewould be non-linear or pyramidal with a bond angle of 107 degrees?

    Thanks in advance for any help,
    Blake
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    (Original post by Blake Jones)
    Hi,

    The question I’m working on is…

    i) use electron pair repulsion theory to deduce the shape of BF3<---NH3
    ii) suggest the shape of the molecule if B is the central atom
    iii) suggest the shape of the molecule if N is the central atom

    On an older post I was looking at for the same question they concluded that BF3 was trigonal planar but I don't understand how BF3 is trigonal planar, surely it has 4 groups of electrons around it, one of which being the lone pair which is a dative bond from the nitrogen?

    Wouldn't this mean it's tetrahedral because ithas 4 groups and then because one of the groups is a lone pair the moleculewould be non-linear or pyramidal with a bond angle of 107 degrees?

    Thanks in advance for any help,
    Blake
    There is a shared pair of electrons between the N and B so it'll be more like this shape:



    So yeah, tetrahedral at both the B and the N.
    • Thread Starter
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    (Original post by alow)
    There is a shared pair of electrons between the N and B so it'll be more like this shape:



    So yeah, tetrahedral at both the B and the N.
    Thanks!
 
 
 
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