VOCABULARY Define. 1. chemical bond. 2. covalent bond. 3. ionic bonding. 4. polar-covalent bond

Transcription

1 Name Date lass Modern hemistry APTER 6 OMEWORK 6-1 (pp ) VOABULARY Define. 1. chemical bond 2. covalent bond 3. ionic bonding 4. polar-covalent bond SKILL BUILDER Use the electronegativity values to classify the bonds that would form between atoms of each of the following elements. Element Electronegativity Element Electronegativity ydrogen () 2.1 Oxygen (O) 3.5 Sodium (Na) 0.9 arbon () 2.5 alcium (a) 1.0 obalt (o) 1.8 Lithium (Li) 1.0 Nitrogen (N) 3.0 Bond Type Bond Type and O N and O and Li and a Na and o N and a Li and N Na and O a and and O ircle the letter of the best answer. 1. A large difference in electronegativity between two atoms in a bond results in a. polar covalent bonding. b. nonpolar covalent bonding. c. ionic bonding. d. repulsion between the two atoms. 2. Which of the following happens when atoms bond with each other? a. The atoms increase in potential energy. b. The potential energy of the compound is maximized. c. Their electronegativity dramatically increases. d. They create arrangements of matter that are more stable. Modern hemistry opyright by olt, Rinehart and Winston. All rights reserved.

2 Name Date lass Modern hemistry APTER 6 OMEWORK 6-2 (pp ) VOABULARY Define. 1. molecule 2. molecular compound 3. molecular formula 4. diatomic molecule 5. chemical formula SKILL BUILDER omplete each sentence. 1. Nature favors chemical bonding because 2. When atoms are drawn together by attractive forces, their potential energy. 3. Potential energy is at a minimum when. 4. Atoms are drawn to each other because the electron-proton attraction is ircle the letter of the best answer. 1. The molecular formula 2 O indicates a molecule a. with two atoms of oxygen bonded with one atom of hydrogen. b. with two atoms of hydrogen bonded with one atom of oxygen. c. that includes only ionic bonds. d. that is diatomic. 2. Which statement is true? a. A molecule can exist only if two of the same type of atom are bonded. b. The strength of attraction between charged particles depends only on the type of atom involved in the bond. c. An atom of any element is a unit that can stand on its own. d. The strength of attraction between charged particles depends on the distance between the atoms involved in the bond. Modern hemistry opyright by olt, Rinehart and Winston. All rights reserved.

3 Name Date lass Modern hemistry APTER 6 OMEWORK 6-3 (pp ) VOABULARY Write true or false for each statement. 1. The bond length is the distance between two bonded atoms at their maximum potential energy. 2. The energy required to form a chemical bond between two neutral atoms is called bond energy. 3. According to the octet rule, chemical compounds tend to form so that each atom has an octet of electrons in its highest energy level. 4. When the orbitals of the hydrogen atoms in a hydrogen molecule overlap, the electron density between the nuclei decreases. SKILL BUILDING On a separate sheet of paper, use Table 6-1 to create a graph comparing bond length to bond energy. Plot bond length on the x-axis (in pm) and bond energy on the y-axis (in kj/mol). hoose ten bonds to portray on the graph. y What does your graph show about the relationship between bond length and bond energy? x ircle the letter of the best answer. 1. Noble-gas atoms are able to exist independently in nature because a. they are exceptions to the octet rule. b. their bond energies are low compared to their bond lengths. c. their electron configurations are more stable than those of other atoms. d. they share electrons in overlapping orbitals with other noble-gas atoms. 2. Which statement is true? a. As atoms are drawn together, the potential energy decreases. b. Potential energy is at a maximum when attractive forces are balanced by repulsive forces. c. The composition of an element is given by its molecular formula. d. ydrogen is the only element that bonds to achieve noble-gas configurations. Modern hemistry opyright by olt, Rinehart and Winston. All rights reserved.

4 Name Date lass Modern hemistry APTER 6 OMEWORK 6-4 (pp ) VOABULARY omplete each sentence. 1. The notation shows only the valence electrons of an atom of a particular element. 2. A lone pair is a pair of electrons that is. 3. A single bond is a covalent bond produced by. 4. a. A structural formula indicates. b. It does not indicate. GRAPI ORGANIZER Make a flow chart to show the steps in drawing the Lewis structure of a compound. Include at least five steps. Then illustrate the steps on your flowchart as you draw the Lewis structure of 4 O. ircle the letter of the best answer. 1. The electron-dot notation of hydrogen is. This configuration proves a. that a hydrogen atom has only one occupied energy level. b. that hydrogen is a noble gas. c. that the n = 1 level of a hydrogen atom contains a single electron. d. both a and c. 2. Which of the following statements is true? a. A pair of dots in electron-dot notation represents an electron pair of a lone atom in a compound. b. Only valence electrons of a particular atom are shown in electron-dot notation. c. A single bond is formed when a single electron brings two atoms together. d. ovalent bond formation involves the electrons closest to the nuclei of the atoms. Modern hemistry opyright by olt, Rinehart and Winston. All rights reserved.

5 Name Date lass Modern hemistry APTER 6 OMEWORK 6-5 (pp ) VOABULARY Define. 1. double bond 2. a. triple bond b. ow is a triple bond shown? 3. resonance 4. resonance structures GRAPI ORGANIZER On a separate sheet of paper, use Table 6-2 on page 173 to create a graph comparing bond length to bond energy. Plot bond length on the x-axis (in pm) and bond energy on the y-axis (in kj/mol). Depict all the bonds shown in the table on your graph. y x What does your graph show about the relationship between bond length and bond energy? Which bonds are strongersingle, double, or triple? ircle the letter of the best answer. 1. The Lewis structure for 2 4 is. This Lewis structure shows that a. the bonds between carbon and hydrogen are double bonds. b. each hydrogen atom has two valence electrons. c. the bond between the carbon atoms is a double bond. d. the bond energies of the carbon-hydrogen bonds are higher than the bond energy of the carbon-carbon bond. 2. Which is the correct Lewis structure for l? a. l b. l c. l d. l Modern hemistry opyright by olt, Rinehart and Winston. All rights reserved.

6 Name Date lass Modern hemistry APTER 6 OMEWORK 6-6 (pp ) VOABULARY omplete each sentence. 1. An ionic compound is 2. The chemical formula of an ionic compound represents 3. A formula unit is 4. A crystal lattice is formed so that 5. Lattice energy is the energy released when SKILL BUILDER On a separate sheet of paper, compare and contrast ionic and molecular compounds. Describe such characteristics as the strength of forces of attraction, melting point, boiling point, hardness, and solubility. Account for the differences between the two types of compounds. ircle the letter of the best answer. 1. Which statement is true of molecular compounds? a. When dissolved in water, they conduct electricity. b. They are hard, brittle substances. c. Their lattice energies are positive rather than negative. d. Some are completely gaseous at room temperature. 2. Which statement is true of ionic compounds? a. The distances between the ions vary throughout the crystal. b. All ionic crystals have the same structure. c. The ions cannot move in the solid state. d. All ionic compounds are able to dissolve in water. Modern hemistry opyright by olt, Rinehart and Winston. All rights reserved.

7 Name Date lass Modern hemistry APTER 6 OMEWORK 6-7 (pp ) VOABULARY Write true or false for each statement. 1. A polyatomic ion is a group of covalently bonded atoms. 2. Nal is a molecular compound. 3. Lattice energy is released when the ions in a crystal lattice are separated from each other. 4. Ionic compounds are electrical conductors in their molten states. 5. An ionic compound is composed of independent, neutral elements that can be isolated from each other. 6. The atoms in molecular compounds are held together by covalent bonds. SKILL BUILDER Each of the compounds listed below is ionic or molecular. Based on the information given, write ionic if the compound is more likely to be ionic than molecular. Write molecular if the compound is more likely molecular than ionic. 1. ompound A is a gas at room temperature. 2. ompound B breaks easily. 3. ompound conducts electricity when dissolved in water. 4. ompound D has a value for lattice energy. 5. ompound E has a low melting point. 6. ompound F is not soluble in water. 7. The components of compound G are held together by electrical attraction. ircle the letter of the best answer. 1. Which statement is true? a. alculating lattice energies helps chemists compare bond strengths in ionic compounds. b. Table salt is a molecular compound. c. Na 2 l 2 is a formula unit. d. Ionic crystals form so that the potential energy of a compound is maximized. 2. Which statement is true? a. Molecular formulas represent the simplest formulas for compounds. b. The forces holding ions together in ionic bonds are relatively weak. c. Intermolecular attractions that hold molecules together are stronger than ionic action. d. A polyatomic ion with a shortage of electrons has a positive charge. Modern hemistry opyright by olt, Rinehart and Winston. All rights reserved.

8 Name Date lass APTER 6 REVIEW hemical Bonding MIXED REVIEW SORT ANSWER Answer the following questions in the space provided. 1. Name the type of energy that is a measure of strength for each of the following types of bonds: a. ionic bond b. covalent bond c. metallic bond 2. Use the electronegativity values shown in Figure 5-20, on page 151 of the text, to determine whether each of the following bonds is nonpolar covalent, polar covalent, or ionic. a. F d. b. Nal e. c. O f. N 3. ow is a hydrogen bond different from an ionic or covalent bond? 4. 2 S and 2 O have similar structures and their central atoms belong to the same group. Yet 2 S is a gas at room temperature and 2 O is a liquid. Use bonding principles to explain why this is true. MODERN EMISTRY APTER 6 MIXED REVIEW 51 RW material copyrighted under notice appearing earlier in this work.

9 Name Date lass MIXED REVIEW continued 5. Why is a polar-covalent bond similar to an ionic bond? 6. Draw a Lewis structure for each of the following formulas. Determine whether the molecule is polar or nonpolar. a. 2 S S b. Ol 2 l l O c. Pl 3 l P l l d. 2 O Oa 52 APTER 6 MIXED REVIEW MODERN EMISTRY RW material copyrighted under notice appearing earlier in this work.