Question

2. In Sidente FeCo,, C4+ cations in the carbonate groups are surrounded by three O2. anions. a) What is the electrostatic valance of the of each C-O bond? b) How many of these bonds can each O make? c) How much charge does the O anion have left for bonding if it is bonded to one C4+*? d) The Fe2* cations in siderite are coordinated by 6 oxygen anions. What is the electrostatic valence of the Fe2+-O bonds? In siderite, each oxygen is bonded to both Fe+ and C4. Based on your answers to c) and d) above, how many bonds does each oxygen make to C4+ and Fe2+ cations? e)

Answer 1

Siderite (FeCO_3)^2 +, structure -Trigonal (Hexagonal Scalenohed) a) implies Electrostatic valance formula rightarrow s = Z/CN where Z = formal charge of the cation CN = Co-ordintation no. Therefore For each C-O bond is 4/3 b) implies Each C-O bond makes O^2-bond, which shown in diagram(above) c) implies Each co-ordinate part have 3 C-O bond, out of 3-bond 2-O^2-is no charge left while that of one O^2-have one anion charge is Left d) implies The Electrostatic valance bond as we known i.e. S = Z/CN = 2/S = 1/4 of Fe^2 + -O bond. e) implies Total 6 Co-ordinated oxygent atom each atom have 2-bond (i.e. Total no. of bond is 12) which are one from O-C^4 + bond and other from O-Fe^2 + bond.