Question

Determine the bond angle for SiO2, BF3, CFCl3, H2CS, CBr4, H2CO, SC2, HB3.

the question ask is to Express your answer using three significant figures...???

thank you!

Answer 1

Here, we are going to find out the bond angles for each molecule.The bond angles can be calculated by using VSEPR theory. The repulsion between the electron groups of the internal atom determines the geometry of the molecule. The best possible geometry of the molecule is that where electron groups have maximum separation between them.

(a) SiO2

The valence electron of Si = 4

Valence electron of O atom = 6

Total valence electrons in SiO2 molecule = 4+2x6 =16 e

The Lewis structure of SiO2 is

From Lewis structure, it is found that SiO2 has two electron groups. Therefore, two bonds repel each other, gives a linear geometry.

Thus, the bond angle of SiO2 is 180o.

(b) BF3

The valence electron of B = 3

Valence electron of F atom =7

Total valence electrons in BF3 molecule = 3+3x7 =24 e

The Lewis structure of BF3 is

From Lewis structure, it is found that BF3 has three electron groups around the central atom which can maximize their separation. Thus it results a trigonal planar geometry having bond angle 120o.

Thus, the bond angle of BF3 is 120o.

(c) CFCl3 (carbon is central)

The valence electron of C =4

Valence...