Chapter 7

Briefly discuss three physical properties of ionic solids that are linked to ionic bonds.

Describe an ionic crystal, and explain why ionic crystals for different compounds might vary in shape.

Determine the ratio of cations to anions in each. a. potassium chloride, a salt substitute b. calcium fluoride, used in the steel industry c. calcium oxide, used to remove sulfur dioxide from power-plant exhaust d. strontium chloride, used in fireworks

Discuss the formation of an ionic bond between zinc and oxygen.

Using electron configurations, diagram the formation of an ionic bond between barium and nitrogen.

Conductors Under certain conditions, ionic compounds conduct an electric current. Describe these conditions, and explain why ionic compounds are not always used as conductors.

Which has the greater lattice energy, CsCl or KCl? \(\mathrm{K}_{2} \mathrm{O}\) or CaO? Explain your choices.

What information do you need to write a correct chemical formula to represent an ionic compound?

When are subscripts used in formulas for ionic compounds?

Discuss how an ionic compound is named.

Using oxidation numbers, explain why the formula \(\mathrm{NaF}_{2}\) is incorrect.

Explain what the name scandium(III) oxide means in terms of electrons lost and gained, and identify the correct formula.

Give the formula for each ionic compound. a. calcium iodide b. silver(I) bromide c. copper (II) chloride d. potassium periodate e. silver(I) acetate

Name each of the following ionic compounds. $$ \begin{array}{l}{\text { a. } \mathrm{K}_{2} \mathrm{O}} \\ {\text { b. } \mathrm{CaCl}_{2}} \\ {\text { c. } \mathrm{Mg}_{3} \mathrm{N}_{2}} \\\ {\text { d. } \mathrm{NaClO}_{2}} \\ {\text { e. } \mathrm{KNO}_{3}}\end{array} $$

Chrome Chromium, a transition metal used in chrome plating, forms both the \(C r^{2+}\) and \(C r^{3+}\) ions. Write the formulas for the ionic compounds formed when each of these ions react with fluorine and oxygen ions.

Which are correct formulas for ionic compounds? For those that are not correct, give the correct formula and justify your answer. $$ \begin{array}{ll}{\text { a. AlCl }} & {\text { c. BaOH }_{2}} \\ {\text { b. } \mathrm{Na}_{3} \mathrm{SO}_{4}} & {\text { d. } \mathrm{Fe}_{2} \mathrm{O}}\end{array} $$

Describe a metallic bond.

Briefly explain why metallic alloys are made.

Briefly describe how malleability and ductility of metals are explained by metallic bonding.

Explain how a metallic bond is similar to an ionic bond.

Brass Copper and zinc are used to form brass, an alloy. Briefly explain why these two metals form a substitutional alloy and not an interstitial alloy.

How is a metallic bond different from an ionic bond?

Silver Briefly explain why silver is a good conductor of electricity.

Steel Briefly explain why steel, an alloy of iron, is used to build the supporting structure of many buildings.

Alloys Describe the difference between the metal alloy sterling silver and carbon steel in terms of the types of alloys involved.

Give the number of valence electrons for atoms of oxygen, sulfur, arsenic, phosphorus, and bromine.

Which ionic compounds would have the greatest lattice energy: NaCl, KCl, or MgCl \(_{2} ?\) Explain your answer.

Give the formula for each ionic compound. a. sodium sulfide b. iron \((\mathrm{III})\) chloride c. sodium sulfate d. calcium phosphate e. zinc nitrate

Cobalt, a transition metal, forms both the \(\mathrm{Co}^{2+}\) and \(\mathrm{Co}^{3+}\) ions. Write the correct formulas, and give the name for the oxides formed by the two different ions.

Gold Briefly explain why gold can be used both in jewelry and as a conductor in electronic devices.

Discuss the formation of the nickel ion with a \(2+\) oxidation number.

Compare the oxyanions sulfate and sulfite.

Using electron-dot structures, diagram the formation of an ionic bond between potassium and iodine.

Magnesium forms both an oxide and a nitride when burned in air. Discuss the formation of magnesium oxide and magnesium nitride when magnesium atoms react with oxygen and nitrogen atoms.

An external force easily deforms sodium metal, while sodium chloride shatters when the same amount of force is applied. Why do these two solids behave so differently?

Name each ionic compound. a. \(\mathrm{CaO}\) b. BaS c. AlPO \(_{4}\) d. \(\operatorname{Ba}(\mathrm{OH})_{2}\) e. \(\operatorname{Sr}\left(\mathrm{NO}_{3}\right)_{2}\)

Predict which solid in each pair will have the higher melting point. Explain your answers. $$ \begin{array}{l}{\text { a. } \mathrm{NaCl} \text { or } \mathrm{CsCl}} \\\ {\text { b. Ag or } \mathrm{Cu}} \\ {\text { c. } \mathrm{Na}_{2} \mathrm{O} \text { or } \mathrm{MgO}}\end{array} $$

Compare and contrast cations and anions.

Observe and Infer Identify the mistakes in the incorrect formulas and formula names, and design a flowchart to prevent the mistakes. $$ \begin{array}{ll}{\text { a. copper acetate }} & {\text { d. disodium oxide }} \\\ {\text { b. } \operatorname{Mg}_{2} \mathrm{O}_{2}} & {\text { e. } \mathrm{Al}_{2} \mathrm{SO}_{43}} \\ {\text { c. } \mathrm{Pb}_{2} \mathrm{O}_{5}}\end{array} $$

Apply Praseodymium is a lanthanide element that reacts with hydrochloric acid, forming praseodymium (III) chloride. It also reacts with nitric acid, forming praseodymium(II) nitrate. Praseodymium has the electron configuration \([\mathrm{Xe}] 4 \mathrm{f}^{3} 6 \mathrm{s}^{2}\) a. Examine the electron configuration, and explain how praseodymium forms a \(3+\) ion. b. Write the correct formulas for both compounds formed by praseodymium.

Hypothesize Look at the locations of potassium and calcium on the periodic table. Form a hypothesis to explain why the melting point of calcium is considerably higher than the melting point of potassium.

Assess Explain why the term delocalized is an appropriate term for the electrons involved in metallic bonding.

Apply All uncharged atoms have valence electrons. Explain why elements such as iodine and sulfur do not have metallic bonds.

Analyze Explain why lattice energy is a negative quantity.

Ionic Compounds Chrysoberyl is a transparent or translucent mineral that is sometimes opalescent. It is composed of beryllium aluminum oxide, BeAl. \(\mathrm{O}_{4}\) . Identify the oxidation numbers of each of the ions found in this compound. Explain the formation of this ionic compound.

You are given a liquid of unknown density. The mass of a graduated cylinder containing 2.00 \(\mathrm{mL}\) of the liquid is 34.68 \(\mathrm{g} .\) The mass of the empty graduated cylinder is 30.00 \(\mathrm{g} .\) Given this information, determine the density of the liquid. (Chapter 2\()\)

A mercury atom drops in energy from \(1.413 \times 10^{-18} \mathrm{J}\) to \(1.069 \times 10^{-18} \mathrm{J.(Chapter} 5 )\) a. What is the energy of the photon emitted by the mercury atom? b. What is the frequency of the photon emitted by the mercury atom? c. What is the wavelength of the photon emitted by the mercury atom?

Which element has the greater ionization energy, chlorine or carbon? (Chapter 6\()\)

Compare and contrast the ways in which metals and nonmetals form ions, and explain why they are different. (Chapter 6\()\)

What are transition elements? (Chapter 6\()\)