Answer to Question #107897 in Chemistry for c

Question

Please predict the bond angles about the central atom in:
Words to choose:bent,trigonometry planar,tetrahedral,trigonal bipyramidal,octahedral,0 non bonding pairs,1 non bonding pairs,2 non bonding pairs,109,5 degrees,120 degrees,180 degrees.Thanks
1)H2S:______ electron-domain geometry with______on S will cause the bond angle to deviate from ideal ________ angles.

Answer 1

Let's consider the electronic structure of the H₂S molecule. Its central atom, S, has 6 electrons in its valence shell (you can see this from the Periodic Table, 3s²3p⁴). Therefore, when two hydrogens share their two electrons with sulphur, sulphur atom has four electron pairs in the valence shell ( 2 pairs shared with hydrogens and 2 lone pairs). In VSEPR notation, this molecule is described as AX₂E₂, where A is the central atom (sulphur), X is the atom linked to the central atom (two hydrogens) and E is the non-bonding electron pair (2 pairs in this case). The electron-domain geometry of AX₂E₂ is bent (or angular). For this geometry, the angle is slightly lower than 109.5°, characteristic for tetrahedral geometry.

Answer: H₂S:bent electron-domain geometry with 2 non bonding pairs on S will cause the bond angle to deviate from ideal 109,5 degrees angles.