Study Guide for Content Mastery Answer Key Chemistry: Matter and Change T179 Name Date Class CHAPTER 8

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1 Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Study Guide for Content Mastery Answer Key Chemistry: Matter and Change T179 Ionic Compounds Forming Chemical Bonds Section 8.1 In your textbook, read about chemical bonds and formation of ions. chemical bond electrons energy level ions noble gases nucleus octet pseudo-noble gas formations valence The force that holds two atoms together is called a(n) (1) chemical bond. Such an attachment may form by the attraction of the positively charged () nucleus of one atom for the negatively charged () electrons of another atom, or by the attraction of charged atoms, which are called (4) ions. The attractions may also involve (5) valence electrons, which are the electrons in the outermost (6) energy level. The (7) noble gases are a family of elements that have very little tendency to react. Most of these elements have a set of eight outermost electrons, which is called a stable (8) octet. The relatively stable electron structures developed by loss of electrons in certain elements of groups 1B, B, A, and 4A are called (9) pseudo-noble gas formations. For each statement below, write or. 10. A positively charged ion is called an anion. 11. Elements in group 1A lose their one valence electron, forming an ion with a 1 charge. 1. Elements tend to react so that they acquire the electron structure of a halogen. 1. A sodium atom tends to lose one electron when it reacts. 14. The electron structure of a zinc ion (Zn ) is an example of a pseudonoble gas formation. 15. A Cl ion is an example of a cation. 16. The ending -ide is used to designate an anion. 17. Nonmetals form a stable outer electron configuration by losing electrons and becoming anions. Study Guide for Content Mastery Chemistry: Matter and Change Chapter 8 4 What is an ionic bond? Section 8. In your textbook, read about forming ionic bonds and the characteristics of ionic compounds. Circle the letter of the choice that best completes the statement or answers the question. 1. An ionic bond is a. attraction of an atom for its electrons. b. attraction of atoms for electrons they share. c. a force that holds together atoms that are oppositely charged. d. the movement of electrons from one atom to another.. The formula unit of an ionic compound shows the a. total number of each kind of ion in a sample. b. simplest ratio of the ions. c. numbers of atoms within each molecule. d. number of nearest neighboring ions surrounding each kind of ion.. The overall charge of a formula unit for an ionic compound a. is always zero. c. is always positive. b. is always negative. d. may have any value. 4. How many chloride (Cl ) ions are present in a formula unit of magnesium chloride, given that the charge on a Mg ion is? a. one-half b. one c. two d. four 5. Ionic bonds generally occur between a. metals. c. a metal and a nonmetal. b. nonmetals. d. noble gases. 6. Salts are examples of a. nonionic compounds. b. metals. c. nonmetals. d. ionic compounds. 7. A three-dimensional arrangement of particles in an ionic solid is called a(n) a. crystal lattice. b. sea of electrons. c. formula unit. d. electrolyte. 8. In a crystal lattice of an ionic compound, a. ions of a given charge are clustered together, far from ions of the opposite charge. b. ions are surrounded by ions of the opposite charge. c. a sea of electrons surrounds the ions. d. neutral molecules are present. 44 Chemistry: Matter and Change Chapter 8 Study Guide for Content Mastery

2 T180 Chemistry: Matter and Change Study Guide for Content Mastery Answer Key Section 8. continued 9. What is the relationship between lattice energy and the strength of the attractive force holding ions in place? a. The more positive the lattice energy is, the greater the force. b. The more negative the lattice energy is, the greater the force. c. The closer the lattice energy is to zero, the greater the force. d. There is no relationship between the two quantities. 10. The formation of a stable ionic compound from ions a. is always exothermic. c. is always endothermic. b. may be either exothermic or endothermic. d. neither absorbs nor releases energy. 11. In electron transfer involving a metallic atom and a nonmetallic atom during ion formation, which of the following is correct? a. The metallic atom gains electrons from the nonmetallic atom. b. The nonmetallic atom gains electrons from the metallic atom. c. Both atoms gain electrons. d. Neither atom gains electrons. Underline the word that correctly describes each property in ionic compounds. 1. Melting point Low High 1. Boiling point Low High 14. Hardness Hard Soft 15. Brittleness Flexible Brittle 16. Electrical conductivity in the solid state Good Poor 17. Electrical conductivity in the liquid state Good Poor 18. Electrical conductivity when dissolved in water Good Poor For each statement below, write or. 19. The crystal lattice of ionic compounds affects their melting and boiling points. 0. The lattice energy is the energy required to separate the ions of an ionic compound. 1. The energy of an ionic compound is higher than that of the separate elements that formed it.. Large ions tend to produce a more negative value for lattice energy than smaller ions do.. Ions that have larger charges tend to produce a more negative lattice energy than ions with smaller charges do. Study Guide for Content Mastery Chemistry: Matter and Change Chapter 8 45 Chemical Formulas and Their Names Section 8. In your textbook, read about communicating what is in a compound and naming ions and ionic compounds. A one-atom ion is called a(n) (1) monatomic ion. The charge of such an ion is equal to the atom s () oxidation number, which is the number of () electrons transferred to or from the atom to form the ion. In ionic compounds, the sum of the charges of all the ions equals (4) zero. Ions made up of more than one atom are called (5) polyatomic ions. If such an ion is negatively charged and includes one or more oxygen atoms, it is called a(n) (6) oxyanion. If two such ions can be formed that contain different numbers of oxygen atoms, the name for the ion with more oxygen atoms ends with the suffix (7) -ate. The name for the ion with fewer oxygen atoms ends with (8) -ite. In the chemical formula for any ionic compound, the chemical symbol for the (9) cation is written first, followed by the chemical symbol for the (10) anion. A(n) (11) subscript is a small number used to represent the number of ions of a given element in a chemical formula. Such numbers are written to the (1) lower right of the symbol for the element. If no number appears, the assumption is that the number equals (1) one. For each formula in Column A, write the letter of the matching name in Column B. Column A Column B e d b c a 14. ClO 15. ClO ClO 17. Cl 18. ClO anion -ate cation electrons zero lower right monatomic one oxidation number -ite oxyanion polyatomic subscript a. chlorate b. hypochlorite c. chloride d. perchlorate e. chlorite 46 Chemistry: Matter and Change Chapter 8 Study Guide for Content Mastery Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.

3 Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Study Guide for Content Mastery Answer Key Chemistry: Matter and Change T181 Section 8. continued For each of the following chemical formulas, write the correct name of the ionic compound represented. You may refer to the periodic table and Table 8.7 for help. 19. NaI sodium iodide 0. CaCl calcium chloride 1. K S potassium sulfide. MgO magnesium oxide. LiHSO lithium hydrogen sulfate 4 4. NH 4 Br ammonium bromide 5. Ca N calcium nitride 6. Cs P cesium phosphide 7. KBrO potassium bromate 8. Mg(ClO) magnesium hypochlorite 9. Li O lithium peroxide 0. Be (PO 4 ) beryllium phosphate 1. (NH 4 ) CO ammonium carbonate. NaBrO sodium bromate. Fe O iron(iii) oxide 4. Fe(IO ) iron(iii) iodate For each of the following ionic compounds, write the correct formula for the compound. You may refer to the periodic table and Table 8.7 for help. 5. beryllium nitride Be N 6. nickel(ii) chloride NiCl 7. potassium chlorite KClO 8. copper(i) oxide Cu O 9. magnesium sulfite MgSO 40. ammonium sulfide (NH 4 ) S 41. calcium iodate Ca(IO ) 4. iron(iii) perchlorate Fe(ClO 4 ) 4. sodium nitride Na N Study Guide for Content Mastery Chemistry: Matter and Change Chapter 8 47 Metallic Bonds and Properties of Metals Section 8.4 In your textbook, read about metallic bonds. Use the diagram of metallic bonding to answer the following questions. 1. What is the name of the model of metallic bonding that is illustrated? electron sea model. Why are the electrons in a metallic solid described as delocalized? They are free to move from one atom to another.. Which electrons from the metal make up the delocalized electrons? the valence electrons 4. Are the metal atoms that are shown cations or anions? How can you tell? Cations; they are positively charged. 5. How do the metallic ions differ from the ions that exist in ionic solids? The electrons are not completely lost by the metal atoms, as they are in an ionic solid. 6. Explain what holds the metal atoms together in the solid. They are bonded by the oppositely charged electron sea that surrounds them. In your textbook, read about the properties of metals. For each property, write yes if the property is characteristic of most metals, or no if it is not. If the property is a characteristic of metals, explain how metallic bonding accounts for the property. 7. Malleable Yes; when the metal is hammered, the delocalized electrons move, keeping the metallic bonds intact. 8. Brittle 9. Lustrous no 10. High melting point 11. Low boiling point no 1. Ductile Yes; when the metal is pulled, the delocalized electrons move, keeping the metallic bonds intact. 1. Poor conduction of heat Yes; the delocalized electrons absorb and release protons. no 14. Good conduction of electricity Yes; the metallic bonds are strong. Yes; the delocalized electrons are mobile. 48 Chemistry: Matter and Change Chapter 8 Study Guide for Content Mastery

4 T18 Chemistry: Matter and Change Study Guide for Content Mastery Answer Key Covalent Bonding The Covalent Bond Section 9.1 In your textbook, read about the nature of covalent bonds. covalent bond molecule sigma bond exothermic pi bond When sharing of electrons occurs, the attachment between atoms that results is called a(n) (1) covalent bond. When such an attachment is formed, bond dissociation energy is released, and the process is () exothermic. When two or more atoms bond by means of electron sharing, the resulting particle is called a(n) () molecule. If the electrons shared are centered between the two atoms, the attachment is called a(n) (4) sigma bond. If the sharing involves the overlap of parallel orbitals, the attachment is called a(n) (5) pi bond. In your textbook, read about single and multiple bonds and bond strength. Circle the letter of the choice that best completes the statement or answers the question. 6. In what form do elements such as hydrogen, nitrogen, and oxygen normally occur? a. as single atoms c. as molecules containing three atoms b. as molecules containing two atoms d. as molecules containing four atoms 7. How many electrons are shared in a double covalent bond? a. none b. one c. two d. four 8. Bond length is the distance between a. two molecules of the same substance. c. the nuclei of two attached atoms. b. the electrons in two attached atoms. d. the orbitals of two attached atoms. 9. Which of the following relationships relating to bond length is generally correct? a. the shorter the bond, the stronger the bond b. the shorter the bond, the weaker the bond c. the shorter the bond, the fewer the electrons in it d. the shorter the bond, the lower the bond dissociation energy Study Guide for Content Mastery Chemistry: Matter and Change Chapter 9 49 Naming Molecules Section 9. In your textbook, read about how binary compounds and acids are named from their formulas. For each statement below, write or. 1. Binary molecular compounds are generally composed of a metal and a nonmetal.. The second element in the formula of a binary compound is named using the suffix -ite.. The prefix tetra- indicates three atoms. 4. The prefix hexa- indicates six atoms. 5. In naming the first element in a formula, the prefix mono- is not used. 6. For binary acids, the hydrogen part of the compound is named using the prefix hydro-. 7. An oxyacid contains only two elements. 8. If the name of the anion of an oxyacid ends in -ate, the acid name contains the suffix -ous. In your textbook, read about naming molecular compounds and oxyacids. For each item in Column A, write the letter of the matching item in Column B. Column A Column B c i g e b d f a h 9. CO 10. CO 11. H CO 1. NH 1. N O HNO 15. HNO 16. HBr 17. HBrO a. b. c. d. e. f. g. h. i. hydrobromic acid dinitrogen tetroxide carbon monoxide nitrous acid ammonia nitric acid carbonic acid bromic acid carbon dioxide 50 Chemistry: Matter and Change Chapter 9 Study Guide for Content Mastery Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.

5 Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Study Guide for Content Mastery Answer Key Chemistry: Matter and Change T18 Molecular Structures Section 9. In your textbook, read about Lewis structures. For each statement below, write or. 1. A structural formula shows the arrangement of the atoms in a molecule.. The central atom in a molecule is the one with the highest electron affinity.. In molecules, hydrogen is always a terminal atom. 4. The number of bonding pairs in a molecule is equal to the number of electrons. 5. To find the total number of electrons available for bonding in a positive ion, you should add the ion charge to the total number of valence electrons of the atoms present. 6. The electrons in a coordinate covalent bond are donated by both the bonded atoms. 7. Resonance occurs when more than one valid Lewis structure can be written for a molecule. 8. Nitrate is an example of an ion that forms resonance structures. 9. The carbon dioxide molecule contains two double bonds. 10. All electrons in an atom are available for bonding. 11. In the sulfate ion (SO 4 ), electrons are available for bonding. 1. When carbon and oxygen bond, the molecule contains ten pairs of bonding electrons. In your textbook, read about resonance structures and exceptions to the octet rule. For each item in Column A, write the letter of the matching item in Column B. Column A Column B c b d a 1. Odd number of valence electrons 14. Fewer than 8 electrons around an atom 15. More than 8 electrons around central atom 16. More than one valid Lewis structure a. O b. BF c. NO d. SF 6 Study Guide for Content Mastery Chemistry: Matter and Change Chapter 9 51 Molecular Shape Section 9.4 In your textbook, read about the VSEPR model. Circle the letter of the choice that best completes the statement. 1. The VSEPR model is used mainly to a. determine molecular shape. c. determine ionic charge. b. write resonance structures. d. measure intermolecular distances.. The bond angle is the angle between a. the sigma and pi bonds in a double bond. c. two terminal atoms and the central atom. b. the nucleus and the bonding electrons. d. the orbitals of a bonding atom.. The VSEPR model is based on the idea that a. there is always an octet of electrons around an atom in a molecule. b. electrons are attracted to the nucleus. c. molecules repel one another. d. shared and unshared electron pairs repel each other as much as possible. 4. The shape of a molecule whose central atom has four pairs of bonding electrons is a. tetrahedral. b. trigonal planar. c. trigonal pyramidal. d. linear. 5. The shape of a molecule that has two covalent single bonds and no lone pairs on the central atom is a. tetrahedral. b. trigonal planar. c. trigonal pyramidal. d. linear. 6. The shape of a molecule that has three single covalent bonds and one lone pair on the central atom is a. tetrahedral. b. trigonal planar. c. trigonal pyramidal. d. linear. In your textbook, read about hybridization. carbon carbon dioxide hybridization sp identical methane sp phosphorus trihydride The formation of new orbitals from a combination or rearrangement of valence electrons is called (7) hybridization. The orbitals that are produced in this way are (8) identical to one another. An example of an element that commonly undergoes such formation is (9) carbon. When this atom combines its three p orbitals and its one s orbital, the orbitals that result are called (10) orbitals. An example of a molecule that has this type of orbital is (11) sp methane. 5 Chemistry: Matter and Change Chapter 9 Study Guide for Content Mastery

6 T184 Chemistry: Matter and Change Study Guide for Content Mastery Answer Key Electronegativity and Polarity Section 9.5 In your textbook, read about electronegativity. Use the table of electronegativities below to answer the following questions. 1 H.0 Li Na K Rb Cs Fr Be Mg Ca Sr Ba Ra Sc Y La Ac 1.1 Ti Zr 1. 7 Hf 1. V Nb Ta 1.5 Electronegativities of Some Elements 4 Cr Mo W Mn Tc Re 1.9 Metal Metalloid Nonmetal 8 Ni Pd.0 1. What is the meaning of the term electronegativity? the tendency of an atom to attract electrons. Which element has the highest electronegativity? What is the numerical value? What are the name and group number of the chemical family that has the highest overall electronegativities? fluorine;.98; halogens; group 7A. Which element has the lowest electronegativity? What is the numerical value? What are the name and group number of the chemical family that has the lowest overall electronegativities? francium; 0.7; alkali metals; group 1A 4. What general trend in electronegativity do you note going down a group? Across a period? Electronegativity tends to decrease. Electronegativity tends to increase. 5. How are the electronegativity values used to determine the type of bond that exists between two atoms? The values are subtracted. In your textbook, read about the properties of covalent compounds. 6 Fe Ru. 76 Os. 7 Co Rh.8 For each statement below, write or. 6. Ionic compounds are usually soluble in polar substances. 7. In a covalent molecular compound, the attraction between molecules tends to be strong. 77 Ir. Study Guide for Content Mastery Chemistry: Matter and Change Chapter Pt. 9 Cu Ag Au.4 0 Zn Cd Hg B.04 1 Al Ga In Tl C Si 1.90 Ge Sn Pb N P.19 As Sb.05 8 Bi O S.58 4 Se.55 5 Te.1 84 Po.0 9 F Cl.16 5 Br.96 5 I At. Section 9.5 continued In your textbook, read about bond polarity. Using the table of electronegativities on the preceding page, circle the letter of the choice that best completes the statement or answers the question. 8. Unequal sharing of electrons between two bonded atoms always indicates a. a nonpolar covalent bond. c. a polar covalent bond. b. an ionic bond. d. a polar molecule. 9. When electronegativities of two bonded atoms differ greatly, the bond is a. polar covalent. b. coordinate covalent. c. polar covalent. d. ionic. 10. What is the electronegativity difference that usually is the dividing line between covalent and ionic bonds? a. 1.0 b. 1.7 c..7 d The symbol is placed next to which of the following? a. the less electronegative atom in a polar covalent bond c. a positive ion b. the more electronegative atom in a polar covalent bond d. the nucleus 1. A nonpolar covalent bond is one in which a. electrons are transferred. c. electrons are shared equally. b. electrons are shared unequally. d. both electrons are provided by the same atom. 1. Molecules containing only polar covalent bonds a. are always polar. c. are always ionic. b. may or may not be polar. d. are always nonpolar. 14. What factor other than electronegativity determines whether a molecule as a whole is polar or not? a. temperature b. its geometry c. its physical state d. its mass 15. Which of the following correctly describes the compound water, H O? a. ionic c. polar overall, with nonpolar covalent bonds b. nonpolar overall, with polar covalent bonds d. polar overall, with polar covalent bonds 16. Which of the following correctly describes the compound carbon tetrachloride, CCl 4? a. ionic c. polar overall, with nonpolar covalent bonds b. nonpolar overall, with polar covalent bonds d. polar overall, with polar covalent bonds 17. A molecule of ammonia, NH, is a. nonpolar because it is linear. b. polar because it is linear. c. nonpolar because there is no electronegativity difference. d. polar because there is an electronegativity difference and the molecule is trigonal pyramidal. 54 Chemistry: Matter and Change Chapter 9 Study Guide for Content Mastery Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.