shape and their bond angles,,?

Question

whats the shape of--

PCl3 ?
PCl5 ?
POCl3 ?

and their bond angles too ?

Answer 1

For PCl3: There are 4 electron densities on the phosphorus (one being a lone electron pair). Therefore Steric Number = 4 with one lone pair. There will be a tetrahedral arrangement, but because of the lone pair, the angle will be slightly less than 109.5 degrees. The shape of the molecule will be Trigonal Pyrimidal.

For PCl5: There are 5 electron densities on the phosphorus (no lone pairs). Therefore Steric Number = 5. The shape of the molecule will be a trigonal bipyramid. The angles between the axial and equatorial chlorines is 90 degrees. The angles between 2 equatorial chlorines would be 120 degrees.

For POCl3: There are 4 electron densities with no lone pairs. Therefore SN=4 with no lone pairs. Therefore the shape of the molecule will be tetrahedral. Approx 109.5 degrees angles.

The most important aspect is to draw the correct Lewis structures. Then you've got it 99% done.

Answer 2

BCL3 = 120 degrees (trigonal planar) BeF2= 180 degrees (linear)

Answer 3

pyramidal - approx 107
trigonal bipyramidal - 120 and 90
tetrahedral - approx 107