General Chemistry I - Test 4

SHORT ANSWER 3 points each. Fill in the blank with the most correct answer.

1. The ____________________ occurs because atoms tend to be more stable when there outer s and p orbitals are 'filled'.

2. A(n) ________________ occurs when an electron is physically transferred between species, and the resulting compound is held together by electrostatic forces.

3. For isoelectronic species, as the charge becomes more ________________, the size of the species increases.

4. Most covalent bonds can be considered _________________, as most of these bonds occur between species of different electronegativities.

5. Multiple bonding must involve atoms of either ___, ___, or ____.

6. __________________ is said to occur whenever there is an 'arbitrary' placement of molecular features - most notably double bonds.

7. The ____ orbitals are used for bonding in those cases that an atom has more than an octet of electrons around it.

8. The _________________ Model (abbr.) is used to help us to understand and describe molecular shapes.

9. Of the four types of HEDR discussed in class, the one that takes up the most space is ______________________________.

10. A polar molecule must have both __________________ and polar bonds.

11. In multiple bonds, the second (and third) bond(s) formed are called ____ bonds, and occur between non-hybridized p orbitals.

12. ______ molecular orbitals are formed when four atomic orbitals in one species combine with four atomic orbitals in a second species.

13. The ____________________ in MO theory is analogous to the 'bonding' in Lewis structures; however, MO theory will allow for non-integral values when describing bonding.

14. ____________________ is observed when a substance is slightly repelled by a magnetic field, and occurs because all electrons in the substance are paired.

15. The strongest evidence for MO theory is the ________magnetic behavior of O2, which cannot be explained by Lewis structures, but can easily be explained by MO theory.

Problems Point totals are shown in parenthesis. Show your work and circle your answers where appropriate for full credit.

16. (15) Determine the Lewis Structure for each of the following species. Items marked with an asterisk (*) indicate 'non-octet' compounds. Indicate any species that would have resonance.






17. (10) Determine the oxidation number for each of the atoms in the following compounds:





18. (15) For the central atom in each of the following Lewis structures determine the name for the electronic shape, the molecular shape, and the hybridization about that atom.


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/ \







:N - H




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18. (15) The molecule NO is a heteronuclear diatomic molecule; however we can make some predictions assuming the behavior is that of the homonuclear diatomic species we have studied. a) Draw the molecular orbital energy-level diagram for the valence shell in NO, and fill in the electrons. b) Is the molecule diamagnetic or paramagnetic? Explain. c) What is the bond order for the bond between nitrogen and oxygen?

EXTRA CREDIT 10 points Draw resonance structures for ClO2