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    I have a pretty good understanding of VSEPR theory and how to predict bond angles etc.

    However, one thing bugs me.

    Supposing I have NH3.... I know that there is only one lone pair and that bond angle is 107.3 degrees.

    Now, what if I were asked to predict the bond angle of PH3 ?

    I know it is around 104 degrees.

    My question is why this decrease in bond angle for these two similar compounds containg elements inn the same group ?

    Does have to do with the electronegativity ?
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    (Original post by Ari Ben Canaan)
    I have a pretty good understanding of VSEPR theory and how to predict bond angles etc.

    However, one thing bugs me.

    Supposing I have NH3.... I know that there is only one lone pair and that bond angle is 107.3 degrees.

    Now, what if I were asked to predict the bond angle of PH3 ?

    I know it is around 104 degrees.

    My question is why this decrease in bond angle for these two similar compounds containg elements inn the same group ?

    Does have to do with the electronegativity ?
    Yes.

    N is smaller and more electronegative. This increases both the LP-BP repulsion and the BP-BP repulsion. But the increase in the latter dominates --> larger HNH bond angle than HPH
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    (Original post by Plato's Trousers)
    Yes.

    N is smaller and more electronegative. This increases both the LP-BP repulsion and the BP-BP repulsion. But the increase in the latter dominates --> larger HNH bond angle than HPH
    One other question.

    What is the reaction mechanism when Ammonia reacts with Ag ions ?

    I know a ligand is formed but what part does Ammonia play ?
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    (Original post by Ari Ben Canaan)
    One other question.

    What is the reaction mechanism when Ammonia reacts with Ag ions ?

    I know a ligand is formed but what part does Ammonia play ?
    Ammonia as a lewis base, a nucleophile, a lone pair donor, a ligand! Get it?
    Beware, Ag(I) prefers linear coordination when complexed.
 
 
 
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