CHEM 1A  Lecture Quiz 2 • Spring 2015
Name:_________________________________________
1. Consider the electron orbital shown to the right.
A. How many radial nodes does this orbital have?
B. How many ANGULAR nodes does this orbital have?
C. Based on your answers above, what is the identity of this orbital?
2. Which orbital below would be the WORST at shielding outer electrons from the nuclear charge?
A. 3d
B. 4p
C. 4d
D. 5d
E. 5s
3. Write the COMPLETE electron configuration for neutral scandium (Sc).
4. How many VALENCE electrons does a neutral tellurium (Te) atom have?
5. How many CORE electrons does a neutral germanium (Ge) atom have?
6. Rank these neutral atoms from SMALLEST to LARGEST: C, Zr, Fr, Ne, He, Sn
SMALLEST: _______
_______
_______
_______
_______
_______ : LARGEST
7. Rank these ions from SMALLEST to LARGEST: Po2-, Sr2+, I-, Ca2+, In3+, Te2SMALLEST: _______
_______
_______
_______
_______
_______ : LARGEST
CsBr, AlN, AlP, CaSe, SrBr2
8. Based on Coulomb’s Law, order the compounds above from SMALLEST lattive energy to LARGEST
lattice energy.
SMALLEST: _______
_______
_______
_______
_______ : LARGEST
For the next two questions, consider the 4 reactions, A. through D. below.
A.
B.
C.
D.
Mg → Mg2+ + 2eMg → Mg + + 1eMg+ → Mg+2 + 1eMg2- → Mg- + 1e-
9. Rank these reactions based on their expected changes in energy (ΔE), from MOST NEGATIVE ΔE to
MOST POSITIVE ΔE.
MOST NEGATIVE ΔE: _______
_______
_______
_______ : MOST POSITIVE ΔE
10. Which of the reactions above (A.-D.) would correspond to the second ionization energy of magnesium?
11. Would the isolated reaction below release energy (ΔE=-) or require energy (ΔE=+)? Explain your
reasoning.
N(g) + 3e- → N3-(g)
12. Write the Lewis dot structure for H2CNCCH.
13. Draw the lowest energy Lewis dot structure for selenite, SeO32- . Draw ALL resonance structures for
this lowest energy depiction of selenite. Be sure to minimize formal charge.
14. The structure below is called metabisulfite and is used extensively in winemaking as a disinfectant,
antioxidant and preservative. Calculate and write the formal charge next to EACH atom I the Lewis
dot structure for metabisulfite.
15. Based on your answer to the previous question, what would be the overall charge of metabisulfite?
16. What is the empirical formula for a compound found to contain 38.8% carbon, 16.2% hydrogen and
45.1% nitrogen by mass? Show your complete work for full credit.
EXTRA CREDIT: 5 points
A. By assuming that the lattice energy of NaCl2 is approximately the same as that of MgCl2, calculate the
change in energy for the reaction below. Using the results of your calculation, why is NaCl2 unlikely to
form as a naturally occurring ionic compound?
Na(s) + Cl2(g) → NaCl2(s) ΔE = ________________
Reference Information:
Lattice Energy of Magnesium Chloride: +2524 kJ/mol
1st Ionization Energy of Sodium: +494 kJ/mol
2nd Ionization Energy of Sodium: +4562 kJ/mol
1st Electron Affinity of Sodium: -53 kJ/mol
Sublimation Energy of Sodium Metal: +107.32 kJ/mol
1st Ionization Energy of Chlorine: +1255 kJ/mol
2nd Ionization Energy of Chlorine: +2297 kJ/mol
1st Electron Affinity of Chlorine: -349 kJ/mol
Bond Energy of Cl—Cl Single Bond: +242.36 kJ/mol