Name…………………………………………………………………. Unit 5: Bonding
Period ……. Review Book: Topic 4
1. Which of the following is the correct electron dot diagram for nitrogen?
3
2. In water, the bond between hydrogen and oxygen is
(1) ionic
(2) polar covalent
(3) nonpolar covalent
(4) metallic
3. The bonds in MgSO4 can be described as
(1) covalent, only
(2) ionic, only
(3) both ionic and covalent
(4) neither ionic nor covalent
4. Which of the following occurs during covalent bonding?
(1) Electrons are lost.
(2) Electrons are gained.
(3) Valence electrons fall from the excited state to the ground state.
(4) Unpaired electrons form pairs.
5. Which of the following is an example of a substance with a nonpolar covalent bond?
(1) HCl (2) Cl2 (3) HClO2 (4) NaCl
6. Which molecule is polar?
(1) H2 (2) CH4 (3) N2 (4) HCl
7. The formula for magnesium fluoride is MgF2. The best explanation for this fact is that when they combine
(1) each of two magnesium atoms lose an electron and a fluorine atom gains two
(2) a magnesium atom loses two electrons and each of two fluorine atoms gains one
(3) a magnesium atom shares two electrons with two fluorine atoms
(4) each of two magnesium atoms share an electron with a fluorine atom
8. When calcium combines with a nonmetal, it usually (1) loses two electrons
(2) gains six electrons
(3) shares two electrons
(4) shares six electrons
9. Which substance will conduct electricity in both the solid phase and the liquid phase?
(1) AgCl (2) H2 (3) Ag (4)HCl
10. Hydrogen bonds are strongest between molecules of
(1) HBr(g) (2) HF(g) (3) HI(g) (4) HCl(g)
11. The strongest hydrogen bonds are formed between molecules of
(1) H2Te (3) H2O (2) H2Se (4) H2S
12. What type of bonds are present in a strip of magnesium ribbon?
(1) covalent (2) metallic
(3) ionic (4) hydrogen bonds
13. Hydrogen bonds are most likely to exist between molecules of
(1) H2 (2) HI (3) CH4 (4) H2O
14. Which substance, in the solid state, is the best conductor of electricity?
(1) Ag (2) NaCl (3) I2 (4) CO2
15. Which is the predominate type of attraction between molecules of HF in the liquid state?
(1) hydrogen bonding (2) ionic bonding
(3) metallic bonding (4) covalent bonding
16. Which substance exists as network of covalent bonds?
(1) Ar (2) Au (3) SiO2 (4) CO2
17. Mobile electrons are a distinguishing characteristic of
(1) an ionic bond (2) a metallic bond
(3) an electrovalent bond (4) a covalent bond
18. What kind of bonds are found in a sample of H2O(s)?
(1) hydrogen bonds, only
(2) covalent bonds, only
(3) both ionic and hydrogen bonds
(4) both covalent and hydrogen bonds
19. Which substance is made up of molecules that are polar?
(1) N2 (2) CH4 (3) H2O (4) CO2
20. Which element consists of positive ions immersed in a "sea" of mobile electrons.?
(1) sulfur (2) calcium (3) nitrogen (4) chlorine
21. Which compound contains ionic bonds?
(1) CaO (2) NO
(3) SiO2 (4) CO2
22. Which of the following solids has the highest melting point?
(1) Na2O (2) H2O
(3) SO2 (4) CO2
23. Which molecule is nonpolar?
(1) CO2 (2) H2O
(3) CO (4) NH3
24. Which substance contains metallic bonds?
(1) Hg (l) (2) NaCl (s)
(3) H2O (l) (4) C6H12O6 (s)
25. Which statement correctly describes diamond and graphite, which are different forms of solid carbon?
(1) They differ in their molecular structure, only.
(2) They differ in their properties, only.
(3) They differ in their molecular structure and properties.
(4) They do not differ in their molecular structure or properties.
26. The carbon atoms in graphite and the carbon atoms in diamond have different
(1) atomic numbers
(2) atomic masses
(3) electronegativities
(4) structural arrangements
27. Given the balanced equation representing a reaction:
Cl2(g) à Cl(g) + Cl(g)
What occurs during this change?
(1) Energy is absorbed and a bond is broken.
(2) Energy is absorbed and a bond is formed.
(3) Energy is released and a bond is broken.
(4) Energy is released and a bond is formed.
28. At standard pressure, a certain compound has a low boiling point and is insoluble in water. At STP, this compound most likely exists as
(1) ionic crystals
(2) metallic crystals
(3) nonpolar molecules
(4) polar molecules
29. A solid substance is an excellent conductor of electricity. The chemical bonds in this substance are most likely
(1) ionic, because the valence electrons are shared between atoms
(2) ionic, because the valence electrons are mobile
(3) metallic, because the valence electrons are stationary
(4) metallic, because the valence electrons are mobile
30. An atom of which element has the greatest attraction for the electrons in a bond with a hydrogen atom?
(1) chlorine (3) silicon
(2) phosphorus (4) sulfur
31. Which compound contains both ionic and covalent bonds?
(1) ammonia (3) sodium nitrate
(2) methane (4) potassium chloride
32. A barium atom attains a stable electron configuration when it bonds with
(1) one chlorine atom
(2) two chlorine atoms
(3) one sodium atom
(4) two sodium atoms
33.Which formula represents an ionic compound?
(1) H2 (3) CH3OH
(2) CH4 (4) NH4Cl
34. Solid samples of the element phosphorus can be white, black, or red in color. The variations in color are due to different
(1) atomic masses
(2) molecular structures
(3) ionization energies
(4) nuclear charges
35. Carbon has three naturally occurring isotopes, C-12, C-13, and C-14. Diamond and graphite are familiar forms of solid carbon. Diamond is one of the hardest substances known, while graphite is a very soft substance. Diamond has a rigid network of bonded atoms. Graphite has atoms bonded in thin layers that are held together by weak forces. Recent experiments have produced new forms of solid carbon called fullerenes. One fullerene, C60, is a spherical, cagelike molecule of carbon.
(a) Determine both the total number of protons and the total number of neutrons in an atom of the naturally occurring carbon isotope with the largest mass number. [1] 6p and 8n
(b) Identify the type of bonding in a fullerene molecule. [1] nonpolar covalent; covalent; a network of covalent bonds
(c) State, in terms of the arrangement of atoms, the difference in hardness between diamond and graphite. [1]
Diamond has atoms bonded strongly in a three-dimensional network. Graphite has atoms that
are held weakly between layers.
36. Draw the Lewis electron-dot structure for the compound magnesium fluoride, MgF2 .
37. At STP, iodine, I2, is a crystal, and fluorine, F2, is a gas. Compare the strength of the intermolecular forces in a sample of I2 at STP to the strength of the intermolecular forces in a sample of F2 at STP. [1]
weaker intermolecular forces in F2
38. Each molecule listed below is formed by sharing electrons between atoms when the atoms within the molecule are bonded together.
Molecule A: Cl2 Molecule B: CCl4 Molecule C: NH3
(a) Draw the electron-dot (Lewis) structure for the NH3 molecule in the space below.
(b) Explain why CCl4 is classified as a nonpolar molecule.
It has a symmetrical structure
(c) Explain why NH3 has stronger intermolecular forces of attraction than Cl2.
NH3 has hydrogen bonds and Cl2 does not.
(d) Explain, in terms of valence electrons, how the bonding in KCl is different from the bonding in molecules A, B,
and C.
In KCl, valence electrons are transferred. In molecules A, B, and C, valence electrons are shared.
39. Nitrogen and carbon dioxide are gases present in the atmosphere.
(a) Draw the electron-dot diagram for a molecule of nitrogen, N2.
(b) Draw the electron-dot diagram for a molecule of carbon dioxide, CO2.
(c) What is the total number of electron pairs shared between the nitrogen atoms in a molecule of nitrogen, N2?
3
(d) State one similarity and one difference between the bonding within a molecule of nitrogen and the bonding
within a molecule of carbon dioxide.
Sim: both share valence electrons, both between nonmetal atoms
Diff: share diff #s of valence electrons; diff atoms
40. Explain, in terms of electronegativity difference, why the bond in a molecule of HF is more polar than the bond in a molecule of HI. [1]
The electronegativity difference between H and F is greater than the electronegativity difference
between H and I.
41. Base your answers to the following questions on the table below and your knowledge of Chemistry.
(a) State evidence that indicates NH3 has stronger intermolecular forces than CF4. [1]
NH3 has a higher boiling point than CF4.
(b) In the space below, draw a Lewis electron-dot diagram for CF4. [1]
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