In: Chemistry
Hi, I need the Lewis Structure, the Molecular Geometry, and polarity of these compounds:
CH2Cl2
BH3
PH3
SF4
PCl5
Thank you very much
Least electronegative atom is the central atom.
Count the valence electrons.
We need to put two electrons between each atom and remaining around the outside.
See Lewis structures in the image attached.
1) CH2Cl2
CH2Cl2 have four regions of electron density around the central C atom. These are all bonding pairs of electrons so the shape of this molecule is tetrahedral.
2) BH3
Molecule has 3 areas of electron repulsion around the central B atom, so the shape is trigonal planar.
3)PH3
Molecule has 3 areas of electron repulsion around the central B atom, so the shape should be trigonal planar. But lone pair on P distorts the structure. That’s why it becomes trigonal pyramidal.
SF4 and PCl5
Both have trigonal bipyramidal geometry. As 4 distinct areas of electron density are around Central atom.