Question

10.35) predict the geometry of the following ions using the electron-pair repulsion model

A) Clo_3²

B) Po_4³²

C) SCN²

D) H₂O¹

Answer 1

I think you have errorneously written the anions so I am giving as per norms

1. ClO₃^- : The central atom is Cl atom.and Cl contains 7 valence electrons

Cl is bonded with 3 oxygen atoms through 1 Cl-O sigma bond and 2 Cl=O pi bonds. 1 lone pair on Cl atom remain non bonded. . According to VSEPR , 4 electron pairs would therefore be arranged to give TETRAHEDRAL in shape

2. PO₄^3-

The central atom is phosphorus which is bonded to one oxygen atom through a pi bond which will be counts as "one electron pair". since there are four electron pairs hence its geometry is tetrahedral.

3. SCN^- : central atom is carbon. It is bonded to two sigma bond hence 2 electron pair hence the geometry is linear (note : pi bonds are not counted in hybridization)

4. H2O : H2O contains O as central atom which has 6 valence shell electrons out of which two are sigma bonded to H atom and the remaining four electron pairs exist as 2 lone pair giving H2O tetrahedral shape. There are two bonding pairs and two lone pairs. The molecular shape is bent