How can I predict the bond angles for #"TeCl"_4# ?
1 Answer
You can predict the bond angles of tellurium tetrachloride by looking at its molecular geometry.
You can determine its molecular geometry by drawing its Lewis structure. The molecule has a total of 34 valence electrons, 6 from the tellurium atom and 7 from each of the four chlorine atoms.
The tellurium atom will the the central atom of the molecule, the four chlorine atoms being bonded to it through single bonds.
)
The tellurium atom will also have one lone pair of electrons attached.
The central atom will have a steric number equal to 5, since the tellurium atom is surrounded by five regions of electron density - four single bonds and one lone pair of electrons.
)
According to VSEPR Theory, the molecule will have a seesaw geometry (
)
Now for the bond angles. The ideal bond angles for a seesaw molecular geometry are
However, repuslion will cause the lone pair of electrons present on the tellurium to distort these angles a bit by pushing the bonding electrons away from it.
As a result, the bond angles will be less than the ideal values -
SIDE NOTE This is true for a tellurium tetrachloride molecule in the gas phase.
