Chapter 8

When aqueous \(\mathrm{H}_{2} \mathrm{SO}_{4}\) is added to an aqueous solution of \(\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}(a q)\), a precipitate forms. (a) What is the precipitate? (b) Write a net ionic equation for the precipitation reaction. (c) Did adding \(\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}(a q)\) to the sulfuric acid neutralize the acid? Explain.

Ammonium ions \(\left(\mathrm{NH}_{4}^{+}\right)\) behave as an acid. (a) Write an equation that shows \(\mathrm{NH}_{4}{\underline{\phantom{xx}}}^{+}(a q)\) behaving as an acid when it reacts with aqueous hydroxide ion. (b) What are the products of neutralizing an aqueous solution of \(\mathrm{NH}_{4} \mathrm{Cl}\) with \(\mathrm{NaOH}\) ?

You need to prepare some calcium nitrate. (a) Write an intact-molecule balanced equation for an acid-base neutralization reaction that could be used to prepare calcium nitrate. (b) Write the net ionic equation for the neutralization.

Write the complete ionic equation and the net ionic equation for the reaction that occurs when the following solutions are mixed, and name the salt formed in each case: (a) \(\mathrm{HBr}(a q)+\mathrm{NaOH}(a q)\) (b) \(\mathrm{Ca}(\mathrm{OH})_{2}(a q)+\mathrm{HNO}_{3}(a q)\) (c) \(\mathrm{Ca}(\mathrm{OH})_{2}(a q)+\mathrm{HBr}(a q)\) (d) \(\mathrm{Mg}(\mathrm{OH})_{2}(a q)+\mathrm{HCl}(a q)\)

When a precipitate forms in water, the water often becomes warmer. What is the source of the heat energy that warms the water?

Consider the covalent bond in \(\mathrm{H}_{2}\). Why must energy be added to break this bond (in other words, what is the added energy used for)?

Consider the ionic bonds between \(\mathrm{Na}^{+}\) ions and \(\underline{\mathrm{Cl}}^{-}\) ions in \(\mathrm{NaCl}(\mathrm{s}) .\) Why must energy be added to break these bonds (in other words, what is the added energy used for)?

Aqueous solutions of sodium sulfide and iron(III) nitrate are combined. (a) Does a precipitation reaction occur? Explain. (b) If it does, write a net ionic equation for the reaction.

Aqueous solutions of calcium chloride and potassium carbonate are combined. (a) Write the formulas for both reactants. (b) Does a precipitation reaction occur? Explain. (c) If it does, write a net ionic equation for the reaction.

Describe what happens when \(\mathrm{CaCl}_{2}(\mathrm{~s})\) and \(\mathrm{NaNO}_{3}(\mathrm{~s})\) are added to the same beaker of water. What, if anything, dissolves, and what, if anything, precipitates?

Suppose you have an aqueous solution containing Cu \(^{2+}\) ions and \(\mathrm{Na}^{+}\) ions. What could you add that would remove the \(\mathrm{Cu}^{2+}\) ions from solution without adding any new type of cations to the solution?

Suppose you have an aqueous solution of \(\mathrm{Pb}^{2+}\) and \(\mathrm{Ba}^{2+}\) ions. (a) How could you remove just the \(\mathrm{Pb}^{2+}\) ions from the solution? (b) How could you remove both the \(\mathrm{Pb}^{2+}\) and the \(\mathrm{Ba}^{2+}\) ions from the solution at the same time?

Nitric acid consists of \(\mathrm{NO}_{3}^{-}\) and a proton, \(\mathrm{H}^{+}\). (a) Draw a Lewis dot diagram for the nitrate ion. (b) Draw a Lewis dot diagram for nitric acid. (Hint: Nitric acid contains an \(\mathrm{O}-\mathrm{H}\) bond. \()\) (c) Which species, nitrate ion or nitric acid, is more likely to be found in aqueous solution? Explain.

Write the intact-molecule equation and the net ionic equation for the neutralization reaction between perchloric acid, \(\mathrm{HClO}_{4}(a q)\), and \(\mathrm{NaOH}(a q)\). What salt is in solution once the reaction is run?

Heptane, \(\mathrm{C}_{7} \mathrm{H}_{16}\), is one of the components of gasoline. Burning heptane in air yields carbon dioxide and water. Balance the equation for this reaction: \(\mathrm{C}_{7} \mathrm{H}_{16}(l)+\mathrm{O}_{2}(g) \rightarrow \mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g)\)

The burning of ethanol, \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\), in air yields carbon dioxide and water. Balance the equation for this reaction: \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}(l)+\mathrm{O}_{2}(g) \rightarrow \mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g)\)

Sodium chloride reacts with bromine gas, \(\mathrm{Br}_{2}\), to produce sodium bromide plus chlorine gas. Write a balanced equation for this reaction.

Indicate which bonds are broken and which are formed when each reaction occurs: (a) \(\mathrm{N}_{2}+3 \mathrm{Br}_{2} \rightarrow 2 \mathrm{NBr}_{3}\) (b) \(\mathrm{P}_{4}+6 \mathrm{H}_{2} \rightarrow 4 \mathrm{PH}_{3}\) (c) \(\mathrm{KF}+\mathrm{NaI} \rightarrow \mathrm{KI}+\mathrm{NaF}\) (d) \(\mathrm{CH}_{4}+\mathrm{Cl}_{2} \rightarrow \mathrm{CH}_{3} \mathrm{Cl}+\mathrm{HCl}\)

Balance the following equation and classify the reaction it represents as combination, decomposition, single-replacement, or double-replacement: \(\mathrm{Fe}+\mathrm{CdCl}_{2} \rightarrow \mathrm{FeCl}_{3}+\mathrm{Cd}\)

Indicate whether each compound is soluble or insoluble in water: (a) \(\mathrm{BaCO}_{3}\) (b) \(\mathrm{K}_{2} \mathrm{~S}\) (c) \(\mathrm{CaSO}_{4}\) (d) \(\mathrm{Mg}\left(\mathrm{NO}_{3}\right)_{2}\) (e) \(\left(\mathrm{NH}_{4}\right)_{3} \mathrm{PO}_{4}\)

Would you expect a reaction in which all reactants are in the gas phase to go faster, slower, or remain at the same rate if the temperature is increased while everything else is held constant? Explain your answer.

Draw dot diagrams for the reactants and products in each equation, and indicate which bonds are broken and which bonds are formed: (a) \(\mathrm{CH}_{4}+\mathrm{I}_{2} \rightarrow \mathrm{CH}_{3} \mathrm{I}+\mathrm{HI}\) (b) \(\mathrm{C}_{2} \mathrm{H}_{4}+\mathrm{F}_{2} \rightarrow \mathrm{FCH}_{2} \mathrm{CH}_{2} \mathrm{~F}\)

Which equations represent chemical reactions: (a) \(\mathrm{CO}_{2}(\mathrm{~s}) \rightarrow \mathrm{CO}_{2}(g)\) (b) \(3 \mathrm{O}_{2}(g) \rightarrow 2 \mathrm{O}_{3}(g)\) (c) \(\mathrm{NaCl}(s)+\mathrm{H}_{2} \mathrm{O}(l) \rightarrow \mathrm{NaOH}(a q)+\mathrm{HCl}(a q)\) (d) \(\mathrm{H}_{2} \mathrm{O}(g)+\mathrm{CH}_{4}(g) \rightarrow \mathrm{CH}_{4}(g)+\mathrm{H}_{2} \mathrm{O}(g)\)

Hydrogen gas is produced when elemental tin reacts with HF to produce hydrogen and tin(II) fluoride. Write the balanced equation for this reaction.

Classify each compound as acid, base, or salt: (a) \(\mathrm{KCl}\) (b) \(\mathrm{CH}_{3} \mathrm{COOH}\) (c) \(\mathrm{Al}(\mathrm{OH})_{3}\) (d) \(\mathrm{H}_{3} \mathrm{BO}_{3}\) (e) \(\mathrm{LiC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\)

Write the balanced chemical equation for the reaction between pentane, \(\mathrm{C}_{5} \mathrm{H}_{12}\), and oxygen gas that produces carbon dioxide and water.

Write the balanced equation, the complete ionic equation, and the net ionic equation for the neutralization reaction that occurs when nitric acid, \(\mathrm{HNO}_{3}\), is mixed with calcium hydroxide, \(\mathrm{Ca}(\mathrm{OH})_{2}\)

Write the balanced chemical equation for the production of \(\mathrm{P}_{2} \mathrm{O}_{5}\) from \(\mathrm{P}\) and \(\mathrm{O}_{2}\).

Write the formula of the precipitate formed when these solutions are mixed: (a) Aluminum nitrate and sodium hydroxide (b) Potassium phosphate and calcium chloride (c) Magnesium sulfate and sodium carbonate

Write the balanced equation for the preparation of iron(III) oxide from iron metal and oxygen gas. What type of reaction is this?

Balance this chemical equation, and classify it as combination, decomposition, single-replacement, or double-replacement: \(\mathrm{H}_{3} \mathrm{PO}_{4}+\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow \mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}+\mathrm{H}_{2} \mathrm{O}\)

Classify each reaction as combination, decomposition, single-replacement, or double-replacement: (a) \(2 \mathrm{NaCl} \rightarrow 2 \mathrm{Na}+\mathrm{Cl}_{2}\) (b) \(\mathrm{Ba}_{3} \mathrm{~N}_{2} \rightarrow 3 \mathrm{Ba}+\mathrm{N}_{2}\) (c) \(\mathrm{Cl}_{2}+2 \mathrm{NaI} \rightarrow 2 \mathrm{NaCl}+\mathrm{I}_{2}\) (d) \(\mathrm{KNO}_{3}+\mathrm{AgBr} \rightarrow \mathrm{AgNO}_{3}+\mathrm{KBr}\)

What is the number of molecules of \(\mathrm{NaOH}\) required to neutralize one molecule of: (a) \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (b) HI (c) \(\mathrm{H}_{3} \mathrm{PO}_{4}\) (d) \(\mathrm{HNO}_{3}\) (e) \(\mathrm{CH}_{3} \mathrm{COOH}\)

Oxygen can be produced by the decomposition of potassium chlorate, \(\mathrm{KClO}_{3}\). The products of the reaction are \(\mathrm{KCl}\) and \(\mathrm{O}_{2}\). Write a balanced equation for the reaction.

Balance each equation: (a) \(\mathrm{Zn}+\mathrm{HCl} \rightarrow \mathrm{ZnCl}_{2}+\mathrm{H}_{2}\) (b) \(\mathrm{Na}_{2} \mathrm{O}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{NaOH}\) (c) \(\mathrm{CH}_{4}+\mathrm{H}_{2} \mathrm{~S} \rightarrow \mathrm{CS}_{2}+\mathrm{H}_{2}\) (d) \(\mathrm{CO}+\mathrm{H}_{2} \rightarrow \mathrm{CH}_{3} \mathrm{O} \mathrm{H}\)

Calcium hydroxide can be used as an antacid to neutralize \(\mathrm{HCl}\), the acid found in the stomach. Water and calcium chloride, \(\mathrm{CaCl}_{2}\), are the products of the reaction. Write the balanced equation for the reaction.

Carbon dioxide gas and calcium oxide are produced when calcium carbonate, \(\mathrm{CaCO}_{3}\), is heated strongly. Write the balanced equation for this process.

Balance this chemical equation and classify it as combination, decomposition, single-replacement, or double-replacement: \(\mathrm{K}_{2} \mathrm{SO}_{3}+\mathrm{S}_{8} \rightarrow \mathrm{K}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}\)

Name the acid and base that combine to form: (a) \(\mathrm{KNO}_{3}\) (b) \(\mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}\) (c) \(\mathrm{Li}_{2} \mathrm{SO}_{4}\) (d) NaI

Mineral compounds containing sulfur are converted to oxygen-containing compounds by a process known as roasting, which involves heating the mineral in the presence of oxygen. In addition to the mineral oxide, sulfur dioxide is also produced. Write the balanced chemical equation for the roasting of zinc sulfide, \(\mathrm{ZnS}\), to produce zinc oxide, \(\mathrm{ZnO}\), plus sulfur dioxide.

When propane gas, \(\mathrm{C}_{3} \mathrm{H}_{8}\), reacts with oxygen gas, carbon dioxide gas and water are produced. Write the balanced equation for the reaction.

Balance this equation and classify it as combination, decomposition, single- replacement, or double-replacement: \(\mathrm{K}_{2} \mathrm{CrO}_{4}+\mathrm{Al}\left(\mathrm{NO}_{3}\right)_{3} \rightarrow \mathrm{Al}_{2}\left(\mathrm{CrO}_{4}\right)_{3}+\mathrm{KNO}_{3}\)

The reaction of carbon monoxide gas with water vapor produces carbon dioxide gas and hydrogen gas. Write the balanced equation for the reaction.

Which anions form compounds that are generally soluble in water: \(\mathrm{CO}_{3}^{2-}, \mathrm{NO}_{3}^{-}, \mathrm{Br}^{-}, \mathrm{SO}_{4}^{2-}, \mathrm{OH}^{-}, \mathrm{PO}_{4}^{3-} ?\)

Sulfur dioxide and water are formed when hydrogen sulfide, \(\mathrm{H}_{2} \mathrm{~S}\), reacts with oxygen gas. Write the balanced equation for the reaction.

A solution containing which anion can be added to separate: (a) \(\mathrm{Na}^{+}(a q)\) from \(\mathrm{Ag}^{+}(a q)\) (b) \(\mathrm{Na}^{+}(a q)\) from \(\mathrm{Ca}^{2+}(a q)\)

Balance this equation and classify it as combination, decomposition, single- replacement, or. double-replacement: \(\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}\)

Write the net ionic equation for the reaction between solutions of: (a) Aluminum nitrate and sodium hydroxide (b) Potassium phosphate and calcium chloride (c) Magnesium sulfate and sodium carbonate

Heating magnesium carbonate results in the production of carbon dioxide and magnesium oxide. Write the balanced equation for this process, and indicate the type of reaction.

Is the reaction \(\mathrm{LiOH}+\mathrm{HCN} \rightarrow \mathrm{H}_{2} \mathrm{O}+\mathrm{LiCN}\) a combination, decomposition, single-replacement, or double-replacement?