Con Chem B: Unit 8 RETAKE REV. – Polarity and Intermolecular Forces
Name___________________________________ Date __________ Teacher _________________
1. Write the range in electronegativity differences for the following:
a. Non-Polar Covalent
b. Polar Covalent
c. Ionic
2. For which of the above types of bonds are electrons shared EQUALLY?
3. For which of the above types of bonds are the electrons shared UNEQUALLY?
4. For which of the above types of bonds are the electrons not shared, but gained or lost.
5. Tell whether the following are Non-Polar Covalent (NPC), Polar Covalent (PC) or Ionic (I).
a. Li - O
e. Br – Br
b. S – O
f. Se – F
c. K – Br
g. C – Br
d. P – S
h. C – N
Use the following Table to answer questions 6 - 7
Hydrogen Sulfide (H2S), Hydrogen Chloride (HCl) and Silane, SiH4, are common covalent bonds with
hydrogen atoms bonded to atoms of third period elements.
Bond
Bond Energy (kJ/mol)
S–H
347
H – Cl
427
Si – H
393
6. Based on the information, which substance would you expect to have the lowest melting and
boiling points?
7. Based on the information, which substance would you expect to have the highest melting and
boiling points?
8. You learned about 3 types of intermolecular forces (hydrogen bonding, dispersion and dipoledipole). Put them in order from WEAKEST TO STRONGEST.
9. Describe each type of intermolecular force.
a. Dipole – Dipole –
b. Dispersion –
c. Hydrogen Bonds –
10. Hydrogen bonds occur when hydrogen bonds with _______________, ________________ or
_________________.
11. Is hydrogen bonding is a special type of ____________________ forces.
12. Which intermolecular force will have LOW melting and boiling points?
13. Which intermolecular force will have HIGH melting and boiling points?
14. Explain why the MOLECULE CCl4 is NON-POLAR even though it has polar bonds?
The following table lists the melting and boiling points for unknown componds. Answer questions 1415 based on the table:
Compound
Melting Point (K)
Boiling Poing (K)
A
1257
1932
B
1432
2012
C
989
1051
D
88
107
15. Which of the four compounds listed would have the STRONGEST intermolecular forces?
16. Which of the four compounds listed would have the WEAKEST intermolecular forces?
Use the following Lewis Dot Structures to identify answer questions 17 - 23
17. CCl4 is polar or non-polar, based on its shape?
18. BeCl2 is polar or non-polar, based on its shape?
19. BBr3 is polar or non-polar, based on its shape?
20. O2 is polar or non-polar, based on its shape?
21. NH3 is polar or non-polar, based on its shape?
22. List all of the above molecules that will exhibit dispersion forces.
23. List all of the above molecules that will exhibit hydrogen bonding.