Determinare le geometrie usando la teoria vsepr. Indicare gli angoli di legame approssimativi in ciascuna molecola e determinare se ogni molecola è polare o non polare a) BCl3 b) PCl5 c) NCl3 d) SO3 e) XeF4 f) HBF2?
Risposta:
Vedi sotto
Spiegazione:
a) #"BCl"_3#
Lo lasciamo come esercizio per lo studente fare questo.
b) #"PCl"_5#
Un altro esercizio, ma ecco un link al struttura di #"PBr"_5# per aiutarvi.
c) #"NCl"_3#
(i) Lewis structure
https://cluster13-files.instructure.com/courses/986898/files/31116480/course%20files/003%20Chapter%209%20Chemical%20Bonding%20I%3A%20%20Lewis%20Theory/Electron%20Dot%20Structures/07048%20bbluejpg
(from usflearn.instructure.com)This is an #"AX"_3"E"# molecule.
(ii) Shape — Trigonal pyramid
http://file2.answcdn.com/answ-cld/image/upload/h_320,c_fill,g_face:center,q_60,f_jpg/v1401098305/ql7oh2p4szvm3yphhcp5png
(from www.answers.com)(iii) Bond angles — slightly less than 109.5°
(iv) Polarity — polar
(D) #"SO"_3#
(i) Lewis structure
(from gallery4share.com)This is an #"AX"_3# system.
(ii) Shape — Trigonal planar
http://glencoe.mcgraw-hill.com/sites/dl/free/007874637x/514757/trigonal_planarjpg
(from www.suggestkeyword.com)(iii) Bond angles — 120°
(iv) Polarity — nonpolar
All bond dipoles cancel, therefore
e) #"XeF"_4#
(i) Lewis structure
http://images.tutorvista.com/cms/images/101/lewis-dot-structure-of-xef4png
(from chemistry.tutorvista.com)This is an #"AX"_4"E"_2# structure.
(ii) Shape — square planar
(iii) Bond angles — 90°
(iv) Polarity — nonpolar
f) #"HBF"_2#
(i) Lewis structure
(from www.uwplatt.edu)This is an #"AX"_3# structure.
(ii) Shape — Trigonal planar
(iii) Bond angles — Approximately 120°.
(iv) Polarity — polar