SCHOOL OF CHEMISTRY
UNIVERSITY OF THE WITWATERSRAND
CHEM 2001
TUTORIAL 2
1. Draw the Lewis structures for the following molecules: (a) Si2H6, (b) AsF5, (c) HCN, (d) HClO4,
(e) OF2.
2.
Draw a Lewis structure, sketch the three-dimensional shape, and name the electron domain
geometry and molecular geometry for the following molecules: (a) PF3, (b) AsF5, (c) GeCl2, (d)
IF3.
3. Predict the molecular geometry for the following molecules: (a) XeF2, (b) XeF4, (c) XeO3, (d)
XeO4.
4. Chlorine forms four oxyanions, ClO-, ClO2-, ClO3-, and ClO4-. Draw the Lewis structures and
then sketch and compare the electronic and molecular geometries of these oxyanions.
5. What angles are associated with orbitals in the following hybridized sets of orbitals? (a) sp,
(b) sp2, (c) sp3, (d) sp3d, (e) sp3d2.
6. Predict the hybridization at each carbon atom for the following molecules: (a) acetone, (b)
acetic acid, (c) tetrachloethene, (d) urea.
7. Using the MO theory, give the electronic configuration for the following species: O2, O2-, O2-2,
F2, F2+, F2-, Ne2, and Ne2+.
8. (a) What is the bond order of each of the species in (7)? (b) Are they diamagnetic or
paramagnetic? (c) What would the application of MO theory predict regarding the stabilities
of these species?
9. Predict the standard enthalpies of the reactions:
(a) 𝑆22− (𝑔) +
1
𝑆 (𝑔)
4 8
→ 𝑆42− (𝑔)
(b) 𝑂22− (𝑔) + 𝑂2 (𝑔) → 𝑂42− (𝑔)
10. Four elements arbitrarily labelled A, B, C, and D have electronegativities 3.8, 3.3, 2.8, and
1.3, respectively. Place the compounds AB, AD, BD, and AC in order of increasing covalent
character.