Chapter 7

Writing and Balancing Chemical Equations What does it mean to say an equation is balanced? Why is it important for an equation to be balanced?

Consider molecular, complete ionic, and net ionic equations. (a) What is the difference between these types of equations? (b) In what circumstance would the complete and net ionic equations for a reaction be identical?

Balance the following equations: (a) \(\mathrm{PCl}_{5}(s)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow \mathrm{POCl}_{3}(l)+\mathrm{HCl}(a q)\) (b) \(\mathrm{Cu}(s)+\mathrm{HNO}_{3}(a q) \longrightarrow \mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}(a q)+\mathrm{H}_{2} \mathrm{O}(I)+\mathrm{NO}(g)\) (c) \(\mathrm{H}_{2}(g)+\mathrm{I}_{2}(s) \longrightarrow \mathrm{HI}(s)\) (d) \(\operatorname{Fe}(s)+\mathrm{O}_{2}(g) \longrightarrow \mathrm{Fe}_{2} \mathrm{O}_{3}(s)\) (e) \(\mathrm{Na}(s)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow \mathrm{NaOH}(a q)+\mathrm{H}_{2}(g)\) (f) \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}(s) \longrightarrow \mathrm{Cr}_{2} \mathrm{O}_{3}(s)+\mathrm{N}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g)\) (g) \(\mathrm{P}_{4}(s)+\mathrm{Cl}_{2}(g) \longrightarrow \mathrm{PCl}_{3}(l)\) (h) \(\mathrm{PtCl}_{4}(s) \longrightarrow \operatorname{Pt}(s)+\mathrm{Cl}_{2}(g)\)

Balance the following equations: (a) \(\mathrm{Ag}(s)+\mathrm{H}_{2} \mathrm{S}(g)+\mathrm{O}_{2}(g) \longrightarrow \mathrm{Ag}_{2} \mathrm{S}(s)+\mathrm{H}_{2} \mathrm{O}(l)\) (b) \(\mathrm{P}_{4}(s)+\mathrm{O}_{2}(g) \longrightarrow \mathrm{P}_{4} \mathrm{O}_{10}(s)\) (c) \(\operatorname{Pb}(s)+\mathrm{H}_{2} \mathrm{O}(l)+\mathrm{O}_{2}(g) \longrightarrow \mathrm{Pb}(\mathrm{OH})_{2}(s)\) (d) \(\operatorname{Fe}(s)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow \mathrm{Fe}_{3} \mathrm{O}_{4}(s)+\mathrm{H}_{2}(g)\) (e) \(\mathrm{Sc}_{2} \mathrm{O}_{3}(s)+\mathrm{SO}_{3}(l) \longrightarrow \mathrm{Sc}_{2}\left(\mathrm{SO}_{4}\right)_{3}(s)\) (f) \(\mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}(a q)+\mathrm{H}_{3} \mathrm{PO}_{4}(a q) \longrightarrow \mathrm{Ca}\left(\mathrm{H}_{2} \mathrm{PO}_{4}\right)_{2}(a q)\) (g) \(\mathrm{Al}(s)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \longrightarrow \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}(s)+\mathrm{H}_{2}(g)\) (h) \(\operatorname{TiCl}_{4}(s)+\mathrm{H}_{2} \mathrm{O}(g) \longrightarrow \mathrm{TiO}_{2}(s)+\mathrm{HCl}(g)\)

Write a balanced molecular equation describing each of the following chemical reactions. (a) Solid calcium carbonate is heated and decomposes to solid calcium oxide and carbon dioxide gas. (b) Gaseous butane, \(\mathrm{C}_{4} \mathrm{H}_{10}\), reacts with diatomic oxygen gas to yield gaseous carbon dioxide and water vapor. (c) Aqueous solutions of magnesium chloride and sodium hydroxide react to produce solid magnesium hydroxide and aqueous sodium chloride. (d) Water vapor reacts with sodium metal to produce solid sodium hydroxide and hydrogen gas.

Write a balanced equation describing each of the following chemical reactions. (a) Solid potassium chlorate, \(\mathrm{KClO}_{3}\), decomposes to form solid potassium chloride and diatomic oxygen gas. (b) Solid aluminum metal reacts with solid diatomic iodine to form solid \(\mathrm{Al}_{2} \mathrm{I}_{6}\) (c) When solid sodium chloride is added to aqueous sulfuric acid, hydrogen chloride gas and aqueous sodium sulfate are produced. (d) Aqueous solutions of phosphoric acid and potassium hydroxide react to produce aqueous potassium dihydrogen phosphate and liquid water.

Aqueous hydrogen fluoride (hydrofluoric acid) is used to etch glass and to analyze minerals for their silicon content. Hydrogen fluoride will also react with sand (silicon dioxide). (a) Write an equation for the reaction of solid silicon dioxide with hydrofluoric acid to yield gaseous silicon tetrafluoride and liquid water. (b) The mineral fluorite (calcium fluoride) occurs extensively in Illinois. Solid calcium fluoride can also be prepared by the reaction of aqueous solutions of calcium chloride and sodium fluoride, yielding aqueous sodium chloride as the other product. Write complete and net ionic equations for this reaction.

A novel process for obtaining magnesium from sea water involves several reactions. Write a balanced chemical equation for each step of the process. (a) The first step is the decomposition of solid calcium carbonate from seashells to form solid calcium oxide and gaseous carbon dioxide. (b) The second step is the formation of solid calcium hydroxide as the only product from the reaction of the solid calcium oxide with liquid water. (c) Solid calcium hydroxide is then added to the seawater, reacting with dissolved magnesium chloride to yield solid magnesium hydroxide and aqueous calcium chloride. (d) The solid magnesium hydroxide is added to a hydrochloric acid solution, producing dissolved magnesium chloride and liquid water. (e) Finally, the magnesium chloride is melted and electrolyzed to yield liquid magnesium metal and diatomic chlorine gas.

From the balanced molecular equations, write the complete ionic and net ionic equations for the following: (a) \(\mathrm{K}_{2} \mathrm{C}_{2} \mathrm{O}_{4}(a q)+\mathrm{Ba}(\mathrm{OH})_{2}(a q) \rightarrow 2 \mathrm{KOH}(a q)+\mathrm{BaC}_{2} \mathrm{O}_{4}(s)\) (b) \(\operatorname{Pb}\left(\mathrm{NO}_{3}\right)_{2}(a q)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \rightarrow \mathrm{PbSO}_{4}(s)+2 \mathrm{HNO}_{3}(a q)\) (c) \(\mathrm{CaCO}_{3}(s)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \longrightarrow \mathrm{CaSO}_{4}(s)+\mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(l)\)

Use the following equations to answer the next four questions: i. \(\mathrm{H}_{2} \mathrm{O}(s) \longrightarrow \mathrm{H}_{2} \mathrm{O}(l)\) ii. \(\mathrm{Na}^{+}(a q)+\mathrm{Cl}^{-}(\mathrm{aq})+\mathrm{Ag}^{+}(a q)+\mathrm{NO}_{3}^{-}(a q) \longrightarrow \mathrm{AgCl}(s)+\mathrm{Na}^{+}(a q)+\mathrm{NO}_{3}^{-}(a q)\) ii. \(\mathrm{CH}_{3} \mathrm{OH}(g)+\mathrm{O}_{2}(g) \longrightarrow \mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g)\) iv. \(2 \mathrm{H}_{2} \mathrm{O}(l) \longrightarrow 2 \mathrm{H}_{2}(g)+\mathrm{O}_{2}(g)\) v. \(\mathrm{H}^{+}(a q)+\mathrm{OH}^{-}(a q) \rightarrow \mathrm{H}_{2} \mathrm{O}(l)\) (a) Which equation describes a physical change? (b) Which equation identifies the reactants and products of a combustion reaction? (c) Which equation is not balanced? (d) Which is a net ionic equation?

Indicate what type, or types, of reaction each of the following represents: (a) \(\mathrm{Ca}(s)+\mathrm{Br}_{2}(l) \longrightarrow \mathrm{CaBr}_{2}(s)\) (b) \(\mathrm{Ca}(\mathrm{OH})_{2}(a q)+2 \mathrm{HBr}(a q) \rightarrow \mathrm{CaBr}_{2}(a q)+2 \mathrm{H}_{2} \mathrm{O}(l)\) (c) \(\mathrm{C}_{6} \mathrm{H}_{12}(l)+9 \mathrm{O}_{2}(g) \longrightarrow 6 \mathrm{CO}_{2}(g)+6 \mathrm{H}_{2} \mathrm{O}(g)\)

Indicate what type, or types, of reaction each of the following represents: (a) \(\mathrm{H}_{2} \mathrm{O}(g)+\mathrm{C}(s) \longrightarrow \mathrm{CO}(g)+\mathrm{H}_{2}(g)\) (b) \(2 \mathrm{KClO}_{3}(s) \longrightarrow 2 \mathrm{KCl}(s)+3 \mathrm{O}_{2}(g)\) (c) \(\mathrm{Al}(\mathrm{OH})_{3}(a q)+3 \mathrm{HCl}(a q) \longrightarrow \mathrm{AlCl}_{3}(a q)+3 \mathrm{H}_{2} \mathrm{O}(l)\) (d) \(\operatorname{Pb}\left(\mathrm{NO}_{3}\right)_{2}(a q)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \longrightarrow \mathrm{PbSO}_{4}(s)+2 \mathrm{HNO}_{3}(a q)\)

Silver can be separated from gold because silver dissolves in nitric acid while gold does not. Is the dissolution of silver in nitric acid an acid-base reaction or an oxidation-reduction reaction? Explain your answer.

Determine the oxidation states of the elements in the following compounds: (a) NaI (b) \(\mathrm{GdCl}_{3}\) (c) \(\operatorname{LiNO}_{3}\) (d) \(\mathrm{H}_{2} \mathrm{Se}\) (e) \(\mathrm{Mg}_{2} \mathrm{Si}\) (f) \(\mathrm{RbO}_{2}\), rubidium superoxide (g) HF

Determine the oxidation states of the elements in the compounds listed. None of the oxygen-containing compounds are peroxides or superoxides. (a) \(\mathrm{H}_{3} \mathrm{PO}_{4}\) (b) \(\mathrm{Al}(\mathrm{OH})_{3}\) (c) \(\mathrm{SeO}_{2}\) (d) \(\mathrm{KNO}_{2}\) (e) \(\operatorname{In}_{2} \mathrm{S}_{3}\) (f) \(\mathrm{P}_{4} \mathrm{O}_{6}\)

Determine the oxidation states of the elements in the compounds listed. None of the oxygen-containing compounds are peroxides or superoxides. (a) \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (b) \(\mathrm{Ca}(\mathrm{OH})_{2}\) (c) BrOH (d) CINO \(_{2}\) (e) \(\mathrm{TiCl}_{4}\) (f) NaH

Classify the following as acid-base reactions or oxidation-reduction reactions: (a) \(\mathrm{Na}_{2} \mathrm{S}(a q)+2 \mathrm{HCl}(a q) \longrightarrow 2 \mathrm{NaCl}(a q)+\mathrm{H}_{2} \mathrm{S}(g)\) (b) \(2 \mathrm{Na}(s)+2 \mathrm{HCl}(a q) \longrightarrow 2 \mathrm{NaCl}(a q)+\mathrm{H}_{2}(g)\) (c) \(\mathrm{Mg}(s)+\mathrm{Cl}_{2}(g) \longrightarrow \mathrm{MgCl}_{2}(s)\) (d) \(\mathrm{MgO}(s)+2 \mathrm{HCl}(a q) \longrightarrow \mathrm{MgCl}_{2}(a q)+\mathrm{H}_{2} \mathrm{O}(l)\) (e) \(\mathrm{K}_{3} \mathrm{P}(s)+2 \mathrm{O}_{2}(g) \longrightarrow \mathrm{K}_{3} \mathrm{PO}_{4}(s)\) (f) \(3 \mathrm{KOH}(a q)+\mathrm{H}_{3} \mathrm{PO}_{4}(a q) \rightarrow \mathrm{K}_{3} \mathrm{PO}_{4}(a q)+3 \mathrm{H}_{2} \mathrm{O}(l)\)

Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations: (a) \(\mathrm{Mg}(s)+\mathrm{NiCl}_{2}(a q) \rightarrow \mathrm{MgCl}_{2}(a q)+\mathrm{Ni}(s)\) (b) \(\mathrm{PCl}_{3}(l)+\mathrm{Cl}_{2}(g) \longrightarrow \mathrm{PCl}_{5}(s)\) (c) \(\mathrm{C}_{2} \mathrm{H}_{4}(g)+3 \mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{CO}_{2}(g)+2 \mathrm{H}_{2} \mathrm{O}(g)\) (d) \(\mathrm{Zn}(s)+\mathrm{H}_{2} \mathrm{SO}_{4}(a q) \longrightarrow \mathrm{ZnSO}_{4}(a q)+\mathrm{H}_{2}(g)\) (e) \(2 \mathrm{K}_{2} \mathrm{S}_{2} \mathrm{O}_{3}(s)+\mathrm{I}_{2}(s) \longrightarrow \mathrm{K}_{2} \mathrm{S}_{4} \mathrm{O}_{6}(s)+2 \mathrm{KI}(s)\) (f) \(3 \mathrm{Cu}(s)+8 \mathrm{HNO}_{3}(a q) \rightarrow 3 \mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}(a q)+2 \mathrm{NO}(g)+4 \mathrm{H}_{2} \mathrm{O}(l)\) 21\. Complete and balance the following acid-base equations: (a) HCl gas reacts with solid Ca(OH) \(_{2}(s)\). (b) A solution of \(\operatorname{Sr}(\mathrm{OH})_{2}\) is added to a solution of \(\mathrm{HNO}_{3}\).

Complete and balance the following acid-base equations: (a) HCl gas reacts with solid Ca(OH) \(_{2}(s)\) (b) A solution of \(\operatorname{Sr}(\mathrm{OH})_{2}\) is added to a solution of \(\mathrm{HNO}_{3}\)

Complete and balance the following acid-base equations: (a) A solution of \(\mathrm{HClO}_{4}\) is added to a solution of LiOH. (b) Aqueous \(\mathrm{H}_{2} \mathrm{SO}_{4}\) reacts with \(\mathrm{NaOH}\) (c) \(\mathrm{Ba}(\mathrm{OH})_{2}\) reacts with HF gas.

Complete and balance the following oxidation-reduction reactions, which give the highest possible oxidation state for the oxidized atoms. (a) \(\mathrm{Al}(s)+\mathrm{F}_{2}(g) \rightarrow\) (b) \(\mathrm{Al}(s)+\operatorname{CuBr}_{2}(a q) \rightarrow\) (single displacement) (c) \(\mathrm{P}_{4}(s)+\mathrm{O}_{2}(g) \rightarrow\) (d) \(\mathrm{Ca}(s)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (products are a strong base and a diatomic gas)

Complete and balance the following oxidation-reduction reactions, which give the highest possible oxidation state for the oxidized atoms. (a) \(\mathrm{K}(s)+\mathrm{H}_{2} \mathrm{O}(l) \rightarrow\) (b) \(\mathrm{Ba}(s)+\mathrm{HBr}(a q) \rightarrow\) (c) \(\operatorname{Sn}(s)+I_{2}(s) \rightarrow\)

Complete and balance the equations for the following acid-base neutralization reactions. If water is used as a solvent, write the reactants and products as aqueous ions. In some cases, there may be more than one correct answer, depending on the amounts of reactants used. (a) \(\mathrm{Mg}(\mathrm{OH})_{2}(s)+\mathrm{HClO}_{4}(a q) \rightarrow\) (b) \(\mathrm{SO}_{3}(g)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (assume an excess of water and that the product dissolves) (c) \(\operatorname{SrO}(s)+\mathrm{H}_{2} \mathrm{SO}_{4}(l) \rightarrow\)

When heated to \(700-800^{\circ} \mathrm{C}\), diamonds, which are pure carbon, are oxidized by atmospheric oxygen. (They bum!) Write the balanced equation for this reaction.

The military has experimented with lasers that produce very intense light when fluorine combines explosively with hydrogen. What is the balanced equation for this reaction?

Write the molecular, total ionic, and net ionic equations for the following reactions: (a) \(\mathrm{Ca}(\mathrm{OH})_{2}(a q)+\mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2}(a q) \rightarrow\) (b) \(\mathrm{H}_{3} \mathrm{PO}_{4}(a q)+\mathrm{CaCl}_{2}(a q) \rightarrow\)

In a common experiment in the general chemistry laboratory, magnesium metal is heated in air to produce \(\mathrm{MgO} . \mathrm{MgO}\) is a white solid, but in these experiments it often looks gray, due to small amounts of \(\mathrm{Mg}_{3} \mathrm{N}_{2}, \mathrm{a}\) compound formed as some of the magnesium reacts with nitrogen. Write a balanced equation for each reaction.

Lithium hydroxide may be used to absorb carbon dioxide in enclosed environments, such as manned spacecraft and submarines. Write an equation for the reaction that involves 2 mol of LiOH per 1 mol of \(\mathrm{CO}_{2}\). (Hint: Water is one of the products.)

Calcium propionate is sometimes added to bread to retard spoilage. This compound can be prepared by the reaction of calcium carbonate, \(\mathrm{CaCO}_{3}\), with propionic acid, \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{CO}_{2} \mathrm{H}\), which has properties similar to those of acetic acid. Write the balanced equation for the formation of calcium propionate.

Complete and balance the equations of the following reactions, each of which could be used to remove hydrogen sulfide from natural gas: (a) \(\mathrm{Ca}(\mathrm{OH})_{2}(s)+\mathrm{H}_{2} \mathrm{S}(g) \rightarrow\) (b) \(\mathrm{Na}_{2} \mathrm{CO}_{3}(a q)+\mathrm{H}_{2} \mathrm{S}(g) \longrightarrow\)

Copper(II) sulfide is oxidized by molecular oxygen to produce gaseous sulfur trioxide and solid copper(II) oxide. The gaseous product then reacts with liquid water to produce liquid hydrogen sulfate as the only product. Write the two equations which represent these reactions.

Write balanced chemical equations for the reactions used to prepare each of the following compounds from the given starting material(s). In some cases, additional reactants may be required. (a) solid ammonium nitrate from gaseous molecular nitrogen via a two-step process (first reduce the nitrogen to ammonia, then neutralize the ammonia with an appropriate acid) (b) gaseous hydrogen bromide from liquid molecular bromine via a one-step redox reaction (c) gaseous \(\mathrm{H}_{2} \mathrm{S}\) from solid \(\mathrm{Zn}\) and \(\mathrm{S}\) via a two-step process (first a redox reaction between the starting materials, then reaction of the product with a strong acid)

Calcium cyclamate \(\mathrm{Ca}\left(\mathrm{C}_{6} \mathrm{H}_{11} \mathrm{NHSO}_{3}\right)_{2}\) is an artificial sweetener used in many countries around the world but is banned in the United States. It can be purified industrially by converting it to the barium salt through reaction of the acid \(\mathrm{C}_{6} \mathrm{H}_{11} \mathrm{NHSO}_{3} \mathrm{H}\) with barium carbonate, treatment with sulfuric acid (barium sulfate is very insoluble), and then neutralization with calcium hydroxide. Write the balanced equations for these reactions.

Complete and balance each of the following half-reactions (steps 2-5 in half- reaction method): (a) \(\operatorname{Sn}^{4+}(a q) \rightarrow \operatorname{Sn}^{2+}(a q)\) (b) \(\left[\mathrm{Ag}\left(\mathrm{NH}_{3}\right)_{2}\right]^{+}(a q) \longrightarrow \mathrm{Ag}(s)+\mathrm{NH}_{3}(a q)\) (c) \(\mathrm{Hg}_{2} \mathrm{Cl}_{2}(s) \longrightarrow \mathrm{Hg}(l)+\mathrm{Cl}^{-}(a q)\) (d) \(\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow \mathrm{O}_{2}(g)\) (in acidic solution) (e) \(\mathrm{IO}_{3}^{-}(a q) \longrightarrow \mathrm{I}_{2}(s)\) (f) \(\operatorname{SO}_{3}^{2-}(a q) \rightarrow \operatorname{SO}_{4}^{2-}(a q)\) (in acidic solution) (g) \(\operatorname{MnO}_{4}^{-}(a q) \rightarrow \mathrm{Mn}^{2+}(a q)\) (in acidic solution) (h) \(\mathrm{Cl}^{-}(a q) \longrightarrow \mathrm{ClO}_{3}^{-}(a q)\) (in basic solution)

Balance each of the following equations according to the half-reaction method: (a) \(\operatorname{Sn}^{2+}(a q)+\mathrm{Cu}^{2+}(a q) \rightarrow \mathrm{Sn}^{4+}(a q)+\mathrm{Cu}^{+}(a q)\) (b) \(\mathrm{H}_{2} \mathrm{S}(g)+\mathrm{Hg}_{2}^{2+}(a q) \longrightarrow \mathrm{H} g(l)+\mathrm{S}(s)\) (in acid) (c) \(\mathrm{CN}^{-}(a q)+\mathrm{ClO}_{2}(a q) \longrightarrow \mathrm{CNO}^{-}(a q)+\mathrm{Cl}^{-}(a q)\) (in acid) (d) \(\mathrm{Fe}^{2+}(a q)+\mathrm{Ce}^{4+}(a q) \rightarrow \mathrm{Fe}^{3+}(a q)+\mathrm{Ce}^{3+}(a q)\) (e) \(\operatorname{HBrO}(a q) \rightarrow \operatorname{Br}^{-}(a q)+\mathrm{O}_{2}(g)\) (in acid)

Balance each of the following equations according to the half-reaction method: (a) \(\mathrm{Zn}(s)+\mathrm{NO}_{3}^{-}(a q) \rightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{N}_{2}(g)\) (in acid) (b) \(\mathrm{Zn}(s)+\mathrm{NO}_{3}^{-}(a q) \longrightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{NH}_{3}(a q)\) (in base) (c) \(\operatorname{CuS}(s)+\mathrm{NO}_{3}^{-}(a q) \longrightarrow \mathrm{Cu}^{2+}(a q)+\mathrm{S}(s)+\mathrm{NO}(g)\) (in acid) (d) \(\mathrm{NH}_{3}(a q)+\mathrm{O}_{2}(g) \longrightarrow \mathrm{NO}_{2}(g)\) (gas phase) (e) \(\mathrm{H}_{2} \mathrm{O}_{2}(a q)+\mathrm{MnO}_{4}^{-}(a q) \longrightarrow \mathrm{Mn}^{2+}(a q)+\mathrm{O}_{2}(g)\) (in acid) (f) \(\mathrm{NO}_{2}(g) \longrightarrow \mathrm{NO}_{3}^{-}(a q)+\mathrm{NO}_{2}^{-}(a q)\) (in base) (g) \(\mathrm{Fe}^{3+}(a q)+\mathrm{I}^{-}(a q) \longrightarrow \mathrm{Fe}^{2+}(a q)+\mathrm{I}_{2}(a q)\)

Write the balanced equation, then outline the steps necessary to determine the information requested in each of the following: (a) The number of moles and the mass of chlorine, \(\mathrm{Cl}_{2}\), required to react with \(10.0 \mathrm{g}\) of sodium metal, \(\mathrm{Na}\), to produce sodium chloride, NaCl. (b) The number of moles and the mass of oxygen formed by the decomposition of \(1.252 \mathrm{g}\) of mercury(II) oxide. (c) The number of moles and the mass of sodium nitrate, \(\mathrm{NaNO}_{3}\), required to produce \(128 \mathrm{g}\) of oxygen. (NaNO \(_{2}\) is the other product.) (d) The number of moles and the mass of carbon dioxide formed by the combustion of \(20.0 \mathrm{kg}\) of carbon in an excess of oxygen. (e) The number of moles and the mass of copper(II) carbonate needed to produce \(1.500 \mathrm{kg}\) of copper(II) oxide. \(\left(\mathrm{CO}_{2}\right.\) is the other product.)

Write the balanced equation, then outline the steps necessary to determine the information requested in each of the following: (a) The number of moles and the mass of Mg required to react with \(5.00 \mathrm{g}\) of \(\mathrm{HCl}\) and produce \(\mathrm{MgCl}_{2}\) and \(\mathrm{H}_{2}\). (b) The number of moles and the mass of oxygen formed by the decomposition of \(1.252 \mathrm{g}\) of silver(I) oxide. (c) The number of moles and the mass of magnesium carbonate, \(\mathrm{MgCO}_{3}\), required to produce \(283 \mathrm{g}\) of carbon dioxide. (MgO is the other product.) (d) The number of moles and the mass of water formed by the combustion of \(20.0 \mathrm{kg}\) of acetylene, \(\mathrm{C}_{2} \mathrm{H}_{2}\), in an excess of oxygen. (e) The number of moles and the mass of barium peroxide, \(\mathrm{BaO}_{2}\), needed to produce \(2.500 \mathrm{kg}\) of barium oxide, \(\mathrm{BaO}\) \(\left(\mathrm{O}_{2}\right.\) is the other product.)

I_ \(_{2}\) is produced by the reaction of 0.4235 mol of \(\mathrm{CuCl}_{2}\) according to the following equation: \(2 \mathrm{CuCl}_{2}+4 \mathrm{KI} \longrightarrow 2 \mathrm{CuI}+4 \mathrm{KCl}+\mathrm{I}_{2}\) (a) How many molecules of I \(_{2}\) are produced? (b) What mass of I \(_{2}\) is produced?

Silver is often extracted from ores such as \(\mathrm{K}\left[\mathrm{Ag}(\mathrm{CN})_{2}\right]\) and then recovered by the reaction \(2 \mathrm{K}\left[\mathrm{Ag}(\mathrm{CN})_{2}\left[(a q)+\mathrm{Zn}(s) \longrightarrow 2 \mathrm{Ag}(s)+\mathrm{Zn}(\mathrm{CN})_{2}(a q)+2 \mathrm{KCN}(a q)\right.\right.\) (a) How many molecules of \(\mathrm{Zn}(\mathrm{CN})_{2}\) are produced by the reaction of \(35.27 \mathrm{g}\) of \(\mathrm{K}\left[\mathrm{Ag}(\mathrm{CN})_{2}\right] ?\) (b) What mass of \(\mathrm{Zn}(\mathrm{CN})_{2}\) is produced?

50\. What mass of silver oxide, \(\mathrm{Ag}_{2} \mathrm{O}\), is required to produce \(25.0 \mathrm{g}\) of silver sulfadiazine, \(\mathrm{AgC}_{10} \mathrm{H}_{9} \mathrm{N}_{4} \mathrm{SO}_{2}\), from the reaction of silver oxide and sulfadiazine? \(2 \mathrm{C}_{10} \mathrm{H}_{10 \mathrm{N}_{4}} \mathrm{SO}_{2}+\mathrm{Ag}_{2} \mathrm{O} \longrightarrow 2 \mathrm{AgC}_{10} \mathrm{H}_{9} \mathrm{N}_{4} \mathrm{SO}_{2}+\mathrm{H}_{2} \mathrm{O}\)

A compact car gets 37.5 miles per gallon on the highway. If gasoline contains 84.2\% carbon by mass and has a density of \(0.8205 \mathrm{g} / \mathrm{mL}\), determine the mass of carbon dioxide produced during a 500 -mile trip \((3.785\) liters per gallon).

What volume of 0.750 M hydrochloric acid solution can be prepared from the HCl produced by the reaction of 25.0 g of NaCl with excess sulfuric acid? \(\mathrm{NaCl}(s)+\mathrm{H}_{2} \mathrm{SO}_{4}(l) \rightarrow \mathrm{HCl}(g)+\mathrm{NaHSO}_{4}(s)\)

What volume of a 0.2089 M KI solution contains enough KI to react exactly with the Cu(NO \(_{3}\) ) in 43.88 mL of a \(0.3842 M\) solution of \(\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2} ?\) \(2 \mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}+4 \mathrm{KI} \longrightarrow 2 \mathrm{CuI}+\mathrm{I}_{2}+4 \mathrm{KNO}_{3}\)

The toxic pigment called white lead, \(\mathrm{Pb}_{3}(\mathrm{OH})_{2}\left(\mathrm{CO}_{3}\right)_{2}\), has been replaced in white paints by rutile, TiO_ \(.\) How much rutile (g) can be prepared from 379 g of an ore that contains \(88.3 \%\) ilmenite (FeTiO \(_{3}\) ) by mass? \(2 \mathrm{FeTiO}_{3}+4 \mathrm{HCl}+\mathrm{Cl}_{2} \longrightarrow 2 \mathrm{FeCl}_{3}+2 \mathrm{TiO}_{2}+2 \mathrm{H}_{2} \mathrm{O}\)

Which of the postulates of Dalton's atomic theory explains why we can calculate a theoretical yield for a chemical reaction?

A student isolated 25 g of a compound following a procedure that would theoretically yield 81 g. What was his percent yield?

Citric acid, \(\mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{7},\) a component of jams, jellies, and fruity soft drinks, is prepared industrially via fermentation of sucrose by the mold Aspergillus niger. The equation representing this reaction is \(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}+\mathrm{H}_{2} \mathrm{O}+3 \mathrm{O}_{2} \longrightarrow 2 \mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{7}+4 \mathrm{H}_{2} \mathrm{O}\) What mass of citric acid is produced from exactly 1 metric ton \(\left(1.000 \times 10^{3} \mathrm{kg}\right)\) of sucrose if the yield is \(92.30 \%\) ?

Toluene, \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{3}\), is oxidized by air under carefully controlled conditions to benzoic acid, \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CO}_{2} \mathrm{H}\), which is used to prepare the food preservative sodium benzoate, \(C_{6} \mathrm{H}_{5} \mathrm{CO}_{2} \mathrm{Na} .\) What is the percent yield of a reaction that converts 1.000 kg of toluene to 1.21 kg of benzoic acid? \(2 \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{3}+3 \mathrm{O}_{2} \longrightarrow 2 \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CO}_{2} \mathrm{H}+2 \mathrm{H}_{2} \mathrm{O}\)

Outline the steps needed to determine the limiting reactant when \(30.0 \mathrm{g}\) of propane, \(\mathrm{C}_{3} \mathrm{H}_{8}\), is bumed with \(75.0 \mathrm{g}\) of oxygen. Determine the limiting reactant.