NAME____________________________________________________
The IMF Challenge
For each pair of compounds below, draw the Lewis Structure. Then use the Odyssey Stockroom to take a look at the molecules. (Note: for some of these molecules, you may need to take a look at the structure on Odyssey before drawing the Lewis Structure. Also the Odyssey structures do not include lone pairs, but your Lewis Structures should.)
The location of the molecules in the Stockroom is noted in parentheses. Make sure to click on the
“Interaction Map” button whenever possible to visualize how partial charges are distributed throughout the molecule. Click the “Shape” button to return to ball and stick structure.
Next, based on molecular structure, determine which would have the stronger IMF’s and therefore a higher melting point, higher boiling point, and a slower evaporation rate. Give a brief explanation.
Now for some trickery: It is very difficult make this determination for 4 of the pairings below.
You need to find these 4 pairs and note why it is so difficult to make this determination.
1) PF
3
(Inorganic: Phosphorus Compounds) and SF
6
(Inorganic: Sulfur Compounds)
WHO WINS?
WHY?
2) IF
5
(Inorganic: Interhalogens) and BrF
5
(Inorganic: Interhalogens)
WHO WINS?
WHY?

3) CH
3
CH
2
OH (or C
2
H
6
O) (Organic: Alcohols) and CH
3
CHO (or C
2
H
4
O) (Organic: Aldehydes)
WHO WINS?
WHY?
4) C
10
H
22
(Organic: Alkanes, Linear) and
1-propanol CH
3
CH
2
CH
2
OH (or C
3
H
8
O) (Organic: Alcohols)
WHO WINS?
WHY?
5) Fool’s Gold FeS
2
(Inorganic: Transition Metals: Iron Comp.) and Citric Acid C
6
H
8
O
7
(Organic: Polycarboxylic Acids)
WHO WINS?
WHY?

6) C
2
H
6
(Organic: Alkanes, Linear) and Si
2
H
6
(Inorganic: Silicon Compounds)
WHO WINS?
WHY?
7) cyclohexanol (C
6
H
12
O) (Organic: Alcohols) and Benzophenone (C
13
H
10
O) (Organic: Ketones)
WHO WINS?
WHY?
8) NH
3
(Inorganic: Nitrogen Compounds) and CH
4
(Organic: Alkanes, Linear)
WHO WINS?
WHY?

9) HF (Inorganic: Hydrogen Halides) and cyclohexane (C
6
H
12
) (Organic: Cycloalkanes)
WHO WINS?
WHY?
10) F
2
(Elements: Group 17) and Br
2
(Elements: Group 17)
WHO WINS?
WHY?
11) NaCl (See NaCl at top of page) and SiO
2
(See Quartz at top of page)
WHO WINS?
WHY?