Question

How can I predict the bond angles for $GeC{{l}_{2}}$ .

Answer 1

The bond angles of $GeC{{l}_{2}}$ can be calculated from VSEPR theory.

Complete answer:
VSEPR theory is defined as the electron pairs surrounding the atom present in the centre that must be arranged in space in such a distance so as to minimize the electrostatic repulsion experienced between them.
The most important rule of the VSEPR theory states that the bond angles about a central atom are those that minimize the overall repulsion which is experienced between the Electron pairs in the valence shell of the atom.
As the interior angle increases, the repulsion forces decrease sharply. As the value of electronegativity of an atom forming a molecule gets increased, the influence of a bonding electron pair decreases.
Multiple bonds behave similar to a single electron pair for the sake of VSEPR bond theory.
Hybridization of an atom can be found out by calculating the summation of lone pairs and sigma bonds.
If a sum of sigma bonds and lone pairs is 2, we have sp hybridization
If a sum of sigma bonds and lone pairs is 3 , we have $s{{p}^{2}}$ hybridization
If a sum of sigma bonds and lone pairs is 4 , we have $s{{p}^{3}}$ hybridization
If a sum of sigma bonds and lone pairs is 5, we have $s{{p}^{3}}d$ hybridization
If a sum of sigma bonds and lone pairs is 6, we have $s{{p}^{3}}{{d}^{2}}$ hybridization.
Now germanium has 4 valence electrons and chlorine has 7 valence electrons so $GeC{{l}_{2}}$ has a total of 18 valence electrons.
Now germanium has a lone pair and is bonded to 2 chlorine atoms so it's steric no is 3.
This corresponds to $A{{X}_{2}}E$ molecule type ,so it's a bent molecular geometry so the bond angle is less than 120 degree.

Note:
The following shapes can be drawn as a result of the distortions:

Bond pair	Lone Pair	Shape
5	0	Trigonal bipyramidal
4	1	See Saw
3	2	T shape
2	3	Linear.