Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Cicada on March 18, 2007, 11:52:37 AM
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Hello, im need to know whether im am correct in determining the VSEPR geometry and polarity the molecules, can someone please let me know if im right or not, thanks.
Adjustments made, are there any errors remaining:
ClO4-:tetrahedral,nonpolar
H2S:tetrahedral,polar
SF6:octahedreal,nonpolar
PCl3:tetrahedral,polar
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perchlorate is not polar because it's totally symmetrical
also SF6 is not polar for the same reason
I would say that H2S is trigonal (just like water). if you count the free electron pairs, you are right
everything else looks good
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I would say that H2S is trigonal (just like water). if you count the free electron pairs, you are right
I would disagree that H2S should be labeled as trigonal. Trigonal, to me, would suggest a trigonal planar geometry where the bond angles are 120o, which is not the case. Here, it would be appropriate to label the geometry as "bent" or "tetrahedral" (depending on whether you want to specify the geometry of the atoms only or the atoms and lone pairs).
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ok, bent sounds better
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but perchlorate has a negative sign, doesnt that count for something?
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the lewis dot diagrams i drew did confirm that perchlorate is totally symmetrical, so i guess there is a difference between an ion and a polar molecule. I did change h2s to tetrahedral however.
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in general the lone pairs should be left out in the description of the molecule shape, so i would prefer bent to tetrahedral for H2S as well.
the same applies to PCl3, which should be described as trigonal pyramidal to differentiate it from tetrahedral molecules, which typically consist of 5 atoms.