This will be a large Monday quiz, probably 30 points.

1. Of the species NO2, NO2+ and NO2-. Which two species should have nearly the same bond lengths? Explain and justify your answer.
2. By looking at formal charges we can sometimes predict the most stable connectivity for a molecule. Consider for a moment NOCl. Cl is almost always a terminal atom, however, N and O can both be a ‘central’ atom. Draw the most stable Lewis structure for ONCl (N in the center) then draw all the possible Lewis structures for NOCl (O in center). For ALL the structures you just drew, indicate the formal charge on each atom. Then, explain which connectivity you expect. (Which connectivity is more stable) EXPLAIN WHY.
3. Consider a calcium ion and a sulfide ion.
a. Which species has a larger ionization energy? Explain using a complete sentence.
b. Which species is bigger? Explain using a complete sentence.
4. The SCN-1 ion has many ‘legitimate’ Lewis structures. (C is central in all)
a. Draw all of them (more than 2, less than 7)
b.Clearly indicate the formal charge on every atom in each structure
c. Clearly indicate which structure you believe is the most stable, and defend your answer.
5. .Consider the following elements: Oxygen, Phosphorus, Tellurium, Iodine, Boron.
a. Which two (when bonded) would form the most polar bond? EXPLAIN
b. Which one has the smallest ionic radius? EXPLAIN
c. Which one would you expect to have the most exothermic electron affinity? EXPLAIN
6. a. Draw all possible Lewis structures of the nitrite ion.
b. On each atom in each structure, clearly indicate the formal charge.
c. Which of the structures is more energetically stable? Why?
d. What is the bond order of each nitrogen-oxygen bond in the ‘real’ structure (not in each resonance structure) ?

Last Weeks Lab:
Zinc Iodide. make sure you watch the screencasts in there as I will be going through the pre-lab schpiel very quickly.

You might find them as a good additional aid to your studying…

As posted by your blue 4 digit number
Grades as of 10/6

Because of that, I will not be providing you with the answers to the questions nor helping you do the problems except to answer questions like ‘I do not understand what the question is asking’. Clarification questions are prefectly fine. “Is this the rigth answer” kind of questions are not.

If you want to know if you did it right, I strongly suggest you search for answers from the crew of people you consult with for in-class problems, each other.