Chemistry 401

Intermediate Inorganic Chemistry

University of Rhode Island

Exam 1

October 6, 2006
open notes, open book

1. The first electron affinity for oxygen is +141 kJ/mol while the second electron affinity is –780 kJ/mol. Briefly account for the difference in magnitude and sign for these two values.

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2. Find the electron configuration and ground state term symbol for a) Ni3+; b) Rh3+; c) Se2–; d) W3+; e) Ag+.

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3. Polarizability is the ability of an electron cloud in an atom or molecule to be distorted by an electric field. How should polarizability relate to Z*? Briefly explain.

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4. Write the Lewis dot structure showing the formal charges, predict the structure including an estimate of all bond angles, and indicate the likely hybrid orbital on the central atom for the following: a) H2CO; b) AsF6; c) ClO4; d) SO3.

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5. About 2 months ago the first report of the cyaphide anion was made. Cyaphide is the phosphorous analog to the cyanide ion, with phosphorous replacing nitrogen. a) Draw the Lewis dot structure for the cyaphide ion and give the formal charges on each atom. Are the formal charges consistent with electronegativity? b) Draw a molecular orbital energy diagram for the cyaphide ion. Give the bond order. Is the bond order consistent with the Lewis structure?

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