Chapter 9

What is a Lewis electron-dot symbol?

Use Lewis electron-dot symbols to show the electron transfer during the formation of each compound from the appropriate atoms. (a) barium bromide (b) potassium sulfide

Use Lewis electron-dot symbols to show the electron transfer during the formation of each compound from the appropriate atoms. (a) beryllium oxide (b) yttrium chloride

What main factors control the magnitude of lattice energies? Give a specific example of a compound that should have a high lattice energy, and explain why its lattice energy is high.

Explain why (a) the lattice energy of NaI is greater than that of KI. (b) the lattice energy of \(\mathrm{MgCl}_{2}\) is greater than that of \(\mathrm{NaCl}\)

Explain why (a) the lattice energy of LiCl is greater than that of LiBr. (b) the lattice energy of \(\mathrm{Na}_{2} \mathrm{O}\) is greater than that of \(\mathrm{NaF}\).

Given that the lattice energy of an ionic solid increases with the charges of the anion and cation, discuss why the formula of \(\mathrm{NaF}\) is not \(\mathrm{NaF}_{2}\).

Describe the main difference between covalent and ionic bonding.

Define the octet rule and rationalize why the rule applies to most compounds made up of representative elements.

Give the characteristics of a correct Lewis structure.

Explain the different behaviors expected from \(\mathrm{HCl}\) and \(\mathrm{Cl}_{2}\) when each is placed between two oppositely charged plates.

What is a polar bond, and under what circumstances does it occur?

Outline the trends in the electronegativities of the representative elements. Which element has the highest electronegativity?

Compare the trends in electronegativity and ionization energy within (a) a group and (b) a period. Explain any differences.

Explain how formal charges are assigned to atoms in Lewis structures.

Describe what is meant by resonance structures.

Discuss factors that relate formal charges in Lewis structures to the relative stabilities of different connectivities of atoms in molecules and relative stabilities of different resonance structures.

What elements are most likely to form electron-deficient molecules?

What is a radical, and why do radicals violate the octet rule?

Define bond dissociation energy. Describe a method that uses bond dissociation energies to calculate approximate enthalpies of chemical reactions.

Explain why the bond dissociation energy for \(\mathrm{HCl}\) is measured exactly, but that for a \(\mathrm{C}-\mathrm{C}\) bond is an average.

Write Lewis electron-dot symbols for elements and ions. Write the Lewis symbol for the following species. (a) a sodium atom (b) a fluorine atom (c) \(\mathrm{O}^{2-}\) (d) \(\mathrm{Mg}^{2+}\)

Write Lewis electron-dot symbols for elements and ions. Write the Lewis symbol for the following species. (a) a sulfur atom (b) \(\mathrm{I}^{-}\) (c) a beryllium atom (d) \(\mathrm{Ga}^{2+}\)

Write Lewis electron-dot symbols for elements and ions. Write the Lewis symbol for the following species. (a) a lithium atom (b) \(\mathrm{S}^{2-}\) (c) a magnesium atom (d) a bromine atom

Write Lewis electron-dot symbols for elements and ions. Write the Lewis symbol for the following species. (a) a potassium atom (b) a nitrogen atom (c) a boron atom (d) \(\mathrm{F}^{-}\)

Represent the formation of ionic compounds through the use of Lewis symbols and describe how the charges and the sizes of ions influence lattice energies. Write the formulas of the ionic compounds that will form from the two pairs of elements given. Of each pair, which has the greater lattice energy? Explain your choice. (a) lithium and oxygen; sodium and sulfur (b) potassium and chlorine; magnesium and fluorine

Represent the formation of ionic compounds through the use of Lewis symbols and describe how the charges and the sizes of ions influence lattice energies. Write the formulas of the ionic compounds that will form from the two pairs of elements given. Of each pair, which has the greater lattice energy? Explain your choice. (a) potassium and sulfur; potassium and chlorine (b) lithium and fluorine; rubidium and chlorine

Represent the formation of ionic compounds through the use of Lewis symbols and describe how the charges and the sizes of ions influence lattice energies. Of the ionic solids \(\mathrm{LiCl}\) and \(\mathrm{LiI}\), which has the greater lattice energy? Explain your choice.

Represent the formation of ionic compounds through the use of Lewis symbols and describe how the charges and the sizes of ions influence lattice energies. Of the ionic solids \(\mathrm{CaO}\) and \(\mathrm{BaO},\) which has the greater lattice energy? Explain your choice.

Represent the formation of ionic compounds through the use of Lewis symbols and describe how the charges and the sizes of ions influence lattice energies. Arrange the following series of compounds in order of increasing lattice energies. (a) \(\mathrm{NaBr}, \mathrm{NaCl}, \mathrm{KBr}\) (b) \(\mathrm{MgO}, \mathrm{CaO}, \mathrm{CaCl}_{2}\) (c) \(\mathrm{LiF}, \mathrm{BeF}_{2}, \mathrm{BeO}\)

Represent the formation of ionic compounds through the use of Lewis symbols and describe how the charges and the sizes of ions influence lattice energies. Arrange the following series of compounds in order of increasing lattice energies. (a) \(\mathrm{LiCl}, \mathrm{NaCl}, \mathrm{BeCl}_{2}\) (b) \(\mathrm{MgO}, \mathrm{MgF}_{2}, \mathrm{MgBr}_{2}\) (c) \(\mathrm{MgCl}_{2}, \mathrm{BeO}, \mathrm{BeCl}_{2}\)

Write Lewis structures of molecules and polyatomic ions. Write the formula of the simplest neutral compound made from the following: (a) carbon and fluorine (b) nitrogen and iodine (c) oxygen and chlorine

Write Lewis structures of molecules and polyatomic ions. Write the formula of the simplest neutral compound made from the following: (a) silicon and hydrogen (b) phosphorus and chlorine (c) sulfur and fluorine

Write Lewis structures of molecules and polyatomic ions. Write the Lewis structure for each of the following compounds. Label electrons as bonding pairs or lone pairs. (a) \(\mathrm{H}_{2} \mathrm{~S}\) (b) \(\mathrm{H}_{2} \mathrm{CO}\) (c) \(\mathrm{PF}_{3}\)

Write Lewis structures of molecules and polyatomic ions. Draw Lewis structures for the following species. (The skeleton is indicated by the way the molecule is written.) (a) \(\mathrm{Cl}_{2} \mathrm{CO}\) (b) \(\mathrm{H}_{3} \mathrm{C}-\mathrm{CN}\)

Write the Lewis structure for the following compounds. (a) \(\mathrm{AsH}_{3}\) (b) ClF (c) \(\mathrm{CF}_{3} \mathrm{OH}\)

Write Lewis structures for these molecules or ions. (a) \(\mathrm{CN}^{-}\) (b) tetrafluoroethylene, \(\mathrm{C}_{2} \mathrm{~F}_{4},\) the molecule from which Teflon is made (c) acrylonitrile, \(\mathrm{CH}_{2} \mathrm{CHCN},\) the molecule from which Orlon is made

Write the Lewis structure for the following species. (a) \(\mathrm{CCl}_{4}\) (b) \(\mathrm{NO}^{+}\) (c) \(\mathrm{BCl}_{4}^{-}\)

Draw a Lewis structure for each of the following molecules or ions. (a) \(\mathrm{CS}_{2}\) (b) \(\mathrm{BF}_{4}\) (c) \(\mathrm{HNO}_{2}\) (where the bonding is in the order \(\mathrm{HONO}\) ) (d) \(\mathrm{OSCl}_{2}\) (where \(\mathrm{S}\) is the central atom)

Describe the periodic trends of electronegativity. Which atom in each of the following pairs has the greate electronegativity? Use only a periodic table to determine your answer. (a) \(\mathrm{Br}, \mathrm{I}\) (b) \(\mathrm{S}, \mathrm{Cl}\) (c) \(\mathrm{C}, \mathrm{N}\)

Describe the periodic trends of electronegativity. Which atom in each of the following pairs has the greate electronegativity? Use only a periodic table to determine your answer. (a) \(O, S\) (b) \(\mathrm{K}, \mathrm{Ge}\) (c) \(\mathrm{Br}, \mathrm{Te}\)

Describe the periodic trends of electronegativity. Arrange the members of each of the following sets of ele ments in order of increasing electronegativity (use only a periodic table to determine your answer). (a) \(\mathrm{Cl}, \mathrm{I}, \mathrm{Br}\) (b) \(\mathrm{Br}\), Ca, Ga (c) \(\mathrm{O}, \mathrm{K}, \mathrm{Ge}\)

Describe the periodic trends of electronegativity. Arrange the members of each of the following sets of ele ments in order of increasing electronegativities. (a) \(\mathrm{Pb}, \mathrm{C}, \mathrm{Sn}, \mathrm{Ge}\) (b) \(\mathrm{S}, \mathrm{Na}, \mathrm{Mg}, \mathrm{Cl}\) (c) \(\mathrm{P}, \mathrm{N}, \mathrm{Sb}, \mathrm{Bi}\) (d) \(\mathrm{Se}, \mathrm{Ba}, \mathrm{F}, \mathrm{Si}, \mathrm{S} \mathrm{c}\)

Predict whether the bonds between the following atoms should be nonpolar covalent, polar covalent, or ionic. (a) \(\mathrm{C}\) and \(\mathrm{H}\) (b) \(\mathrm{K}\) and \(\mathrm{F}\) (c) \(\mathrm{O}\) and \(\mathrm{O}\) (d) \(\mathrm{Be}\) and \(\mathrm{F}\)

Predict whether the bonds between the following atoms should be nonpolar covalent, polar covalent, or ionic. (a) \(\mathrm{Li}\) and \(\mathrm{O}\) (b) \(\mathrm{F}\) and \(\mathrm{Cl}\) (c) \(\mathrm{S}\) and \(\mathrm{S}\) (d) \(\mathrm{Na}\) and \(\mathrm{I}\)

For each pair of bonds, indicate which has the greater polarity, and show the direction of the dipole moment (use Figure 9.9 if necessary). (a) \(\mathrm{N}-\mathrm{O}, \mathrm{C}-\mathrm{O}\) (b) \(\mathrm{Si}-\mathrm{Ge}, \mathrm{Ge}-\mathrm{C}\) (c) \(\mathrm{S}-\mathrm{H}, \mathrm{O}-\mathrm{H}\) (d) \(\mathrm{B}-\mathrm{C}, \mathrm{B}-\mathrm{Si}\)

For each pair of bonds, indicate the more polar bond, and use an arrow to show the direction of polarity in each bond. (a) \(\mathrm{C}-\mathrm{O}\) and \(\mathrm{C}-\mathrm{N}\) (b) \(\mathrm{P}-\mathrm{Br}\) and \(\mathrm{P}-\mathrm{Cl}\) (c) \(\mathrm{B}-\mathrm{O}\) and \(\mathrm{B}-\mathrm{S}\) (d) \(\mathrm{B}-\mathrm{F}\) and \(\mathrm{B}-\mathrm{I}\)

Which molecule has the most polar bond: \(\mathrm{N}_{2}, \mathrm{BrF}\), or ClF? Use an arrow to show the direction of polarity in each bond.

Given the bonds \(\mathrm{C}-\mathrm{N}, \mathrm{C}-\mathrm{H}, \mathrm{C}-\mathrm{Br},\) and \(\mathrm{S}-\mathrm{O},\) (a) which atom in each is the more electronegative? (b) which of these bonds is the most polar?

Write the Lewis structures showing formal charge for the following species. (a) \(\mathrm{NO}_{2}^{-}\) (b) \(\mathrm{OCS}\) (c) \(\mathrm{SO}_{3}\)