Molecular Shapes; the VSEPR Model (Sections)
Draw the Lewis structure for each of the following molecules or ions, and predict their electron-domain and molecular geometries: (a) AsF3, (b) CH3+, (c) BrF3, (d) ClO3-, (e) XeF2, (f) BrO2-
Molecular shapes according to VSEPR model:a)Arsenic has five valence electrons. It unitizes three electrons to form bonds with three fluorineatoms. Hence, the number of non- bonding electron pairs is one in As.The Lewis dot structure ofAsF is as follows. 3The above structure will shows that Lewis structure of AsF mole3le has four electron pairsaround the central atom. Therefore geometry of the molecule is Tetrahedral.As there is one non bonded electron pair, the molecular geometry is Trigonal pyramidal.b)In ion have three valence electrons. It utilizes these three electrons to form bonds withthree hydrogen atoms. The Lewis dot structure of ion is as follows.The ion has three electron domains around the central atom. Hence, the electron domaingeometry is planar triangular. As there are no non-bonding electrons in the central atom themolecular geometry is also same.c)In molecule, the central bromine atom has seven e=valence electrons. It forms three bondswith three fluorine atoms. Hence, it has two non- bonding pairs of electrons. The Lewis structureof is as follows.\nThe molecule has five electrons pairs with Trigonal Bipyramidal geometry.As there are two non-bonded electron pairs in the molecule, the molecular geometry is T-shape.d)The Lewis structure of is as follows.In molecule has four electron pairs around the geometry is tetrahedral. Because of thepresence of one non bonded electron pair, the molecular geometry of the ion is Trigonalpyramidal.e)The Lewis dot structure of is as follows.Due to the presence of five electron pairs the molecular geometry of molecule is Trigonalbipyramidal.But the presence of three non – bonded electron pairs makes the molecule linear shaped.f)The Lewis structure of is as follows.\nDue to the presence of four electron pairs the molecular geometry of the molecule is Tetrahedral.But the presence of two non-bonded electron pairs makes the ion bent shaped.