Solution
Number of electron pairs ( EP ) = V + M - C + A 2 ; V = Group number of central atom ; M = - H , - X , - OH . . . . monovalent groups attached to central atom ; C = Charge of cation ; A = Charge of anion ; V = 2 , 3 . 4 , 5 , 6 , 7 , 8 respectively for 2 nd , 13 th , 14 th , 15 th , 16 th , 17 th , 18 th group elements ; Number bond pairs , BP ( according to VSEPR theory ) = Number of atoms directly attached to central atom ; = 4 , 4 , 3 , 3 respectively in XeO 4 , ClO 4 - XeO 3 , , ClO 3 - ; * * * According to VSEPR theory , double bond and triple bond are counted as one bond pair only ; If the bonded atom is Oxygen . . . . . Magnitude of Oxidation state of central atom = Total bonds ; Number of atoms directly attached to central atom = sigma bonds ; Total bonds - sigma bonds = pi bonds ; Number lone pairs on central atom ( LP ) = EP - BP ; = 0 , 0 , 1 , 1 respectively in XeO 4 , ClO 4 - XeO 3 , , ClO 3 - ; XeO 4 - ' 4 ' bp + ' 0 ' lp on central atom ; sp 3 - Tetrahedral ; Total 8 lone pairs / molecule ; 8 lone pairs on bonded atoms ; . . . . Orientation of electron pairs . . . . Tetrahedral ; ClO 4 - - ' 4 ' bp + ' 0 ' lp on central atom ; sp 3 - Tetrahedral ; Total 9 lone pairs / ion ; 9 lone pairs on bonded atoms ; . . . . Orientation of electron pairs . . . . Tetrahedral ; XeO 3 - ' 3 ' bp + ' 1 ' lp on central atom ; sp 3 - Pyramidal ; Total 7 lone pairs / molecule ; 6 lone pairs on bonded atoms . . . . Orientation of electron pairs . . . . Tetrahedral ; ClO 3 - - ' 3 ' bp + ' 1 ' lp on central atom ; sp 3 - Pyramidal ; Total 8 lone pairs / ion ; 7 lone pairs on bonded atoms . . . . Orientation of electron pairs . . . . Tetrahedral ; Note ; Each double bonded oxygen atom has ' 2 ' lone pairs on it ; Each single bonded oxygen atom has ' 3 ' lone pairs on it ; XeO 4 : Magnitude of Oxidation state of central atom = Total bonds = 8 ; Number of atoms directly attached to central atom = sigma bonds = 4 ; Total bonds - sigma bonds = pi bonds = 4 - - ' 0 ' pπ - pπ and ' 4 ' dπ - pπ bonds ; ClO 4 - : Magnitude of Oxidation state of central atom = Total bonds = 7 ; Number of atoms directly attached to central atom = sigma bonds = 4 ; Total bonds - sigma bonds = pi bonds = 3 - - ' 0 ' pπ - pπ and ' 3 ' dπ - pπ bonds ; XeO 3 : Magnitude of Oxidation state of central atom = Total bonds = 6 ; Number of atoms directly attached to central atom = sigma bonds = 3 ; Total bonds - sigma bonds = pi bonds = 3 - - ' 0 ' pπ - pπ and ' 3 ' dπ - pπ bonds ; ClO 3 - : Magnitude of Oxidation state of central atom = Total bonds = 5 ; Number of atoms directly attached to central atom = sigma bonds = 3 ; Total bonds - sigma bonds = pi bonds = 2 - - ' 0 ' pπ - pπ and ' 2 ' dπ - pπ bonds ;