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    Do all molecules containing atoms with different electronegativites have permanent dipole-dipole forces/ interactions between molecules? Obviously excluding symmetrical molecules in which the dipoles cancel out.

    Thanks!
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    Yes, everything apart from all the exceptions :p:

    There are two factors electronegativity difference and lack of symmetry - both are needed for permanent dipole forces to come into play.
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    (Original post by Farseer)
    Yes, everything apart from all the exceptions :p:

    There are two factors electronegativity difference and lack of symmetry - both are needed for permanent dipole forces to come into play.
    I've just found a qu with PH3. I'm assuming that because it's in group 5 it will have a similar structure to NH3 (with a lone pair from the P), but how am I supposed to know that P is more electronegative than H?

    And thank you btw
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    (Original post by annaj97)
    I've just found a qu with PH3. I'm assuming that because it's in group 5 it will have a similar structure to NH3 (with a lone pair from the P), but how am I supposed to know that P is more electronegative than H?

    And thank you btw
    You are supposed to be aware that hydrogen is relatively more electropositive than all the other non-metals.
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    (Original post by annaj97)
    I've just found a qu with PH3. I'm assuming that because it's in group 5 it will have a similar structure to NH3 (with a lone pair from the P), but how am I supposed to know that P is more electronegative than H?

    And thank you btw
    You should know the electronegativities of common elements based on the general trend - as P is just under N on the periodic table it should be fairly electronegative compared to H. Failing that, it is unlikely that two elements have the same electronegativity (which is more or less is not as important).
 
 
 
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