Worksheet on HRW’s Chapter 6: Molecular Compounds
This chatper contains five simple sections except the last one.
I would encourage teachers to do open book test on this chapter as kids do need periodic table as well as some material from the chapter that better be used as reference than memorize.
Some of the concepts are too advanced, particularly the mlecular geometry. Could have been avoided or introduced later when needed to explain something else.
- Introduction to Chemical bonds
- Covalent Bonding and Molecular Compounds
- Ionic Bonding and Ionic Compounds
- Metallic Bonding
- Molecular Geometry
Time permitting, I would love to continue the hypothetical atom house story and build on that to introduce formation of compounds and attractions/repulsions in thus formed complex structures.
For now, kids should be able to benefit from just doing this practice worksheet using open book.
Parents and teachers can coach using the questions which are all from HRW book. These are good set of questions to help quickly get most of the concepts from the chapter into their brains if they are strapped for time and can’t read the lengthy and verbose chapter.
Another very useful worksheets is here
Introduction to Chemical Bonding
1. What is a chemical bond?
2. Identify and define the three types of chemical boding?
3.What is the relationship between electronegativity and the ionic character of a chemical bond?
4a) What is the meaning of the term polar, as applied to chemical bonding?
4b) Distinguish between polar-covalent and nonpolar-covalent bonds.
5.What determines whether atoms will form chemical bonds?
6. Determine the electronegativity difference, the probable and bond type, and the more electronegative atom with respect to bonds formed between the following pairs of atoms
|Electronegativity difference||Bond type||Electronegative atom in the bond|
|H and I|
|S and O|
|K and Br|
|Si and Cl|
|K and Cl|
|Se and S|
|C and H|
7. Assign rank to the bonding pairs in order of increasing covalent character with 1 being least covalent and 7 being the most covalent.
|H and I|
|S and O|
|K and Br|
|Si and Cl|
|K and Cl|
|Se and S|
|C and H|
8. Use orbital notation to illustrate the bonding in each of the following molecules:
|Hydrogen Fluoride, HF|
9. The lattice energy of sodium chloride, NaCl, is -787.5 kJ/mol. The lattice energy of potassium chloride, KCL, is -715 kJ/mol. In which compound is the bonding between ions stronger? Why?
Covalent Bonding and Molecular Compounds
10. What is a molecule?
11.a) What determines bond length?
11.b) How are bond energies and bond lengths related?
12. Describe the general location of the electrons in a covalent bond.
13. As applied to covalent bonding, what is meant by an unshared or line pair of electrons?
14.Describe the octet rule in terms of noble-gas configurations and potential energy?
15.Determine the number of valence electrons in an atom of each of the following elements
16. When drawing Lewis structures, which atom is usually the central atom?
17. Distinguish between single, double, and triple covalent bonds by defining each and providing an illustration of each type.
18. In writing Lewis structures, how is the need for multiple bonds generally determined?
19. Use electron-dot notation to illustrate the number of valence electrons present in one atom of each of the following elements.
20. Use electron-dot structure to demonstrate the formation of ionic compounds involving the following elements:
|Na and S|
|Ca and O|
|Al and S|
21. Draw Lewis structures for each of the following molecules
|One C and four F atoms|
|Two C and one Se atom|
|Two N and one I atoms|
|One Si and one Br atoms|
|One C and one Br atoms|
|One C, one Cl, and three H atoms|
22. Determine the type of hybrid orbitals formed by the boron atom in a molecule of boron fluoride, BF3.
23.Draw Lewis structures for each of the following molecules. Show resonance structures if they exist.
24. Draw Lewis structures for each of the following molecules. Show resonance structures if they exist.
|H2 C2 02–|
Ionic Bonding and Ionic Compounds
25.a) What is an ionic compound?
25.b) In what forms do most ionic compounds occur?
26.a) What is a formula unit?
26.b) What are the components of one formula unit of CaF2
27.a) What is lattice energy?
27.b) What is the relationship between lattice energy and the strength of ionic bonding?
28.a) How do ionic and molecular compounds compare in terms of melting points, boiling points, and ease of vaporization?
28.b) What accounts for the observed difference in the properties of ionic and molecular compounds?
28.c) Cite three physical properties of ionic compounds?
29.a) What is a polyatomic ion?
29.b) Give two examples of polyatomic ions?
29.c) In what form do such ions often occur in nature?
30.a ) How do the properties of metals differ from those of both ionic and molecular compounds?
30.b) What specific property of metals accounts for their unusual electrical conductivity?
31. What properties of metals contribute to their tendency to form metallic bonds?
32.a) What is metallic bonding?
32.b)how can the strength of metallic bonding be measured?
33.a) How is the VSEPR theory used to classify molecules?
33.b) What molecular geometry would be expected for F2 and HF
34)ccording to the VSEPR theory, what molecular geometries are associated with the following
35. Describe the role of each of the following in predicting molecular geometries:
a) Unshared electron pairs
b) Double bonds
36.a) What are hybrid orbitals?
36.b) What determines the number of hybrid orbitals produced by the hybridization of an atom?
37.a) What are intermolecular forces?
37.b) How do these forces compare in strength with hose in ionic and metallic bonding?
38.What is the relationship between electronegativity and the polarity of a chemical bond?
39.a) What are dipole-dipole forces?
39.b) What determined the polarity of a molecule?
40.a) What is meant by an induced dipole?
40.b) What is the everyday importance of this type of intermolecular force?
41.a) What is hydrogen bonding?
41.b) What accounts for its extraordinary strength?
42. What are London dispersion forces?
43. According the VSEPR theory, what molecular geometries are associated with the following types of molecules?
44. Use hybridization to explain the bonding in methane, CH4
45. For each of the following polar molecules, indicate the direction of the resulting dipole:
46. For each of the following polar molecules, indicate the direction of the resulting dipole:
47. On the basis of individual bond polarity and orientation, determine whether each of the following molecules would be polar or nonpolar:
48. Draw a Lewis structure for each of the following molecules, and then use the VSEPR theory to predict the molecular geometry of each:
49. Draw a Lewis structure for each of the following polyatomic ions, and then use the VSEPR theory to determine the geometry of each:
Note: this is meant for use by kids, teachers, and parents working with this text book. Please don’t copy. Follow copy right notice of original HRW book. The questions are word-for-word from the book and therefore please don’t copy this into any commerical works based ont these questions.