Question

The formula for the oxyanion ortho-arsenite is AsO33-. The charge minimized Lewis structure gives an AsO bond order of _______ per AsO bond and _______ (obeys or disobeys) the octet rule. This puts a formal charge of _______ on each _______ atom. According to VSEPR, the shape of the electron groups is _______ and the molecule itself can be considered _______. The bonds in the molecule are _______ (polar or nonpolar) and the molecule itself is _______ (polar or nonpolar).

Answer 1

The formula for the oxyanion ortho-arsenite is AsO₃^3-. The charge minimized Lewis structure gives an AsO bond order of    1    per AsO bond and    disobeys    the octet rule. This puts a formal charge of     -1    on each     O     atom. According to VSEPR, the shape of the electron groups is     tetrahedral      and the molecule itself can be considered      trigonal pyramidal       . The bonds in the molecule are     polar     and the molecule itself is      polar     .

AsO bond order = Valency of the peripheral atom + (Charge on Acid Radical / Total number of peripheral atoms) = 2 + (-3/3) = 1

No of electrons in the valence shell of As = 5 + 3 + 3 (for three negative charge ) = 11