Bonding: Free Response Practice
1. Draw the VSEPR, 3-D representation, for CH2F2 and CF4.
a. Identify the AXE formula, geometry, and bond angle for each.
b. Determine which, if any of the two molecules, is polar
c. Account for any difference in dipole moment
2. NF3 and PF5 are both stable compounds. Write the Lewis dot structures for these molecules.
a. On the basis of their structures, account for the fact that NF3 and PF5 are stable
molecules but NF5 is not.
b. Draw the VSEPR structures for each stable molecule
c. Identify the geometry and bond angle of each
3. Given the following compounds: LiF NaCl KBr CsI
a. Place these in order of increasing melting point
b. Explain your reasoning using bonding principles.
4. Given the following compounds/ions: CO CO2 CO32a. Draw the Lewis Dot Structures for each, including resonance structures where
applicable.
b. Which of these species has the shortest C-O bond length? Explain your reasoning.
c. Predict the molecular shapes for each.
5. Use simple structures and bonding models to account for each of the following.
a. The bond length between two carbon atoms is shorter in C2H4 than in C2H6
b. The H-N-H bond angle is 109.5 in NH3
c. The bond lengths in SO3 are all identical and are shorter than a sulfur-oxygen single
bond.
d. The ion I3- is linear
6. Given the following compounds: SO2 SF6 SCl4 SCl2
a. Draw the Lewis Dot Structures for each of the compounds
b. Identify how the sulfur atom is hybridized in each of the compounds
c. Draw the VSEPR structures for the compounds
d. Determine the geometry and bond angle for each
7. Given the following bond energies, calculate the H for the reaction of methane with chlorine
and fluorine to form Freon-12. Is the reaction endothermic or exothermic?
CH4 + 2 Cl2 + 2 F2
Bond
C-H
C-F
C-Cl
Cl-Cl
F-F
H-F
H-Cl
Energy (kJ/mol)
413
485
339
239
154
565
427
CF2Cl2 + 2 HF + 2 HCl