第4章化学反応の量的関係

Key Concepts and Summary重要な概念とまとめ

Chemical reactions are classified according to similar patterns of behavior. A large number of important reactions are included in three categories: precipitation, acid-base, and oxidation-reduction (redox). Precipitation reactions involve the formation of one or more insoluble products. Acid-base reactions involve the transfer of hydrogen ions between reactants. Redox reactions involve a change in oxidation number for one or more reactant elements. Writing balanced equations for some redox reactions that occur in aqueous solutions is simplified by using a systematic approach called the half-reaction method.

化学反応は、似た振る舞いの型に従って分類される。重要な反応の多くは、沈殿反応、酸塩基反応、酸化還元反応（レドックス反応）の三つの分類に含まれる。沈殿反応では、一種類以上の不溶性生成物が生じる。酸塩基反応では、反応物間で水素イオンが移る。酸化還元反応では、反応物を構成する一種類以上の元素の酸化数が変化する。水溶液中で起こる酸化還元反応の中には、半反応式法という系統的な方法を使うと、係数のつり合った式を書きやすくなるものがある。

Chemistry End of Chapter Exercises化学・章末問題

Exercises 12–41練習問題 12–41

Exercise 12問題 12

Use the following equations to answer the next four questions:

次の反応式を使って、その後の四つの問いに答えなさい。

H_{2} O (s) ⟶ H_{2} O (l)

H_{2} O (s) ⟶ H_{2} O (l)

ii.

{Na}^{+} (a q) + {Cl}^{−} (aq) + {Ag}^{+} (a q) + {NO}_{3}^{−} (a q) ⟶ AgCl (s) + {Na}^{+} (a q) + {NO}_{3}^{−} (a q)

ii.

{Na}^{+} (a q) + {Cl}^{−} (aq) + {Ag}^{+} (a q) + {NO}_{3}^{−} (a q) ⟶ AgCl (s) + {Na}^{+} (a q) + {NO}_{3}^{−} (a q)

iii.

{CH}_{3} OH (g) + O_{2} (g) ⟶ {CO}_{2} (g) + H_{2} O (g)

iii.

{CH}_{3} OH (g) + O_{2} (g) ⟶ {CO}_{2} (g) + H_{2} O (g)

iv.

2 H_{2} O (l) ⟶ 2 H_{2} (g) + O_{2} (g)

iv.

2 H_{2} O (l) ⟶ 2 H_{2} (g) + O_{2} (g)

H^{+} (a q) + {OH}^{−} (a q) ⟶ H_{2} O (l)

H^{+} (a q) + {OH}^{−} (a q) ⟶ H_{2} O (l)

(a) Which equation describes a physical change?

(a) どの式が物理変化を表しているか。

(b) Which equation identifies the reactants and products of a combustion reaction?

(b) どの式が燃焼反応の反応物と生成物を示しているか。

(d) Which is a net ionic equation?

(d) どれが正味のイオン反応式か。

Exercise 13問題 13

Indicate what type, or types, of reaction each of the following represents:

次のそれぞれが、どの種類の反応を表すか示しなさい。複数の種類に該当する場合は、それらを挙げなさい。

(a)

Ca (s) + {Br}_{2} (l) ⟶ {CaBr}_{2} (s)

(a)

Ca (s) + {Br}_{2} (l) ⟶ {CaBr}_{2} (s)

(b)

Ca {(OH)}_{2} (a q) + 2 HBr (a q) ⟶ {CaBr}_{2} (a q) + 2 H_{2} O (l)

(b)

Ca {(OH)}_{2} (a q) + 2 HBr (a q) ⟶ {CaBr}_{2} (a q) + 2 H_{2} O (l)

(c)

C_{6} H_{12} (l) + 9 O_{2} (g) ⟶ 6 {CO}_{2} (g) + 6 H_{2} O (g)

(c)

C_{6} H_{12} (l) + 9 O_{2} (g) ⟶ 6 {CO}_{2} (g) + 6 H_{2} O (g)

Solution解き方

(a) oxidation-reduction (addition); (b) acid-base (neutralization); (c) oxidation-reduction (combustion)

(a) 酸化還元（付加）、(b) 酸塩基（中和）、(c) 酸化還元（燃焼）

Exercise 14問題 14

Indicate what type, or types, of reaction each of the following represents:

次のそれぞれが、どの種類の反応を表すか示しなさい。複数の種類に該当する場合は、それらを挙げなさい。

(a)

H_{2} O (g) + C (s) ⟶ CO (g) + H_{2} (g)

(a)

H_{2} O (g) + C (s) ⟶ CO (g) + H_{2} (g)

(b)

{2KClO}_{3} (s) ⟶ 2 KCl (s) + 3 O_{2} (g)

(b)

{2KClO}_{3} (s) ⟶ 2 KCl (s) + 3 O_{2} (g)

(c)

Al {(OH)}_{3} (a q) + 3 HCl (a q) ⟶ {AlCl}_{3} (a q) + 3 H_{2} O (l)

(c)

Al {(OH)}_{3} (a q) + 3 HCl (a q) ⟶ {AlCl}_{3} (a q) + 3 H_{2} O (l)

(d)

Pb {({NO}_{3})}_{2} (a q) + H_{2} {SO}_{4} (a q) ⟶ {PbSO}_{4} (s) + 2 {HNO}_{3} (a q)

(d)

Pb {({NO}_{3})}_{2} (a q) + H_{2} {SO}_{4} (a q) ⟶ {PbSO}_{4} (s) + 2 {HNO}_{3} (a q)

Exercise 15問題 15

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.

銀は硝酸に溶けるが金は溶けないため、銀を金から分離できる。銀が硝酸に溶ける反応は、酸塩基反応か、それとも酸化還元反応か。理由を説明しなさい。

Solution解き方

It is an oxidation-reduction reaction because the oxidation state of the silver changes during the reaction.

反応中に銀の酸化状態が変化するので、酸化還元反応である。

Exercise 16問題 16

Determine the oxidation states of the elements in the following compounds:

次の化合物中の元素の酸化状態を求めなさい。

(a) NaI

(b) GdCl₃

(d) H₂Se

(e) Mg₂Si

(f) RbO₂, rubidium superoxide

(f) RbO₂、超酸化ルビジウム

(g) HF

Exercise 17問題 17

Determine the oxidation states of the elements in the compounds listed. None of the oxygen-containing compounds are peroxides or superoxides.

次に挙げる化合物に含まれる元素の酸化状態を求めなさい。酸素を含む化合物に、過酸化物や超酸化物はない。

(a) H₃PO₄

(b) Al(OH)₃

(d) KNO₂

(e) In₂S₃

(f) P₄O₆

Solution解き方

(a) H +1, P +5, O −2; (b) Al +3, H +1, O −2; (c) Se +4, O −2; (d) K +1, N +3, O −2; (e) In +3, S −2; (f) P +3, O −2

Exercise 18問題 18

Determine the oxidation states of the elements in the compounds listed. None of the oxygen-containing compounds are peroxides or superoxides.

次に挙げる化合物に含まれる元素の酸化状態を求めなさい。酸素を含む化合物に、過酸化物や超酸化物はない。

(a) H₂SO₄

(b) Ca(OH)₂

(d) ClNO₂

(e) TiCl₄

(f) NaH

Exercise 19問題 19

Classify the following as acid-base reactions or oxidation-reduction reactions:

次の反応を、酸塩基反応または酸化還元反応に分類しなさい。

(a)

{Na}_{2} S (a q) + 2 HCl (a q) ⟶ 2 NaCl (a q) + H_{2} S (g)

(a)

{Na}_{2} S (a q) + 2 HCl (a q) ⟶ 2 NaCl (a q) + H_{2} S (g)

(b)

2 Na (s) + 2 HCl (a q) ⟶ 2 NaCl (a q) + H_{2} (g)

(b)

2 Na (s) + 2 HCl (a q) ⟶ 2 NaCl (a q) + H_{2} (g)

(c)

Mg (s) + {Cl}_{2} (g) ⟶ {MgCl}_{2} (s)

(c)

Mg (s) + {Cl}_{2} (g) ⟶ {MgCl}_{2} (s)

(d)

MgO (s) + 2 HCl (a q) ⟶ {MgCl}_{2} (a q) + H_{2} O (l)

(d)

MgO (s) + 2 HCl (a q) ⟶ {MgCl}_{2} (a q) + H_{2} O (l)

(e)

K_{3} P (s) + 2 O_{2} (g) ⟶ K_{3} {PO}_{4} (s)

(e)

K_{3} P (s) + 2 O_{2} (g) ⟶ K_{3} {PO}_{4} (s)

(f)

3 KOH (a q) + H_{3} {PO}_{4} (a q) ⟶ K_{3} {PO}_{4} (a q) + 3 H_{2} O (l)

(f)

3 KOH (a q) + H_{3} {PO}_{4} (a q) ⟶ K_{3} {PO}_{4} (a q) + 3 H_{2} O (l)

Solution解き方

(a) acid-base; (b) oxidation-reduction: Na is oxidized, H⁺ is reduced; (c) oxidation-reduction: Mg is oxidized, Cl₂ is reduced; (d) acid-base; (e) oxidation-reduction: P³⁻ is oxidized, O₂ is reduced; (f) acid-base

(a) 酸塩基、(b) 酸化還元：Naが酸化され、H⁺が還元される、(c) 酸化還元：Mgが酸化され、Cl₂が還元される、(d) 酸塩基、(e) 酸化還元：P³⁻が酸化され、O₂が還元される、(f) 酸塩基

Exercise 20問題 20

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:

次の各反応式について、酸化される原子と還元される原子、それぞれの酸化状態の変化、および酸化剤と還元剤を挙げなさい。

(a)

Mg (s) + {NiCl}_{2} (a q) ⟶ {MgCl}_{2} (a q) + Ni (s)

(a)

Mg (s) + {NiCl}_{2} (a q) ⟶ {MgCl}_{2} (a q) + Ni (s)

(b)

{PCl}_{3} (l) + {Cl}_{2} (g) ⟶ {PCl}_{5} (s)

(b)

{PCl}_{3} (l) + {Cl}_{2} (g) ⟶ {PCl}_{5} (s)

(c)

C_{2} H_{4} (g) + 3 O_{2} (g) ⟶ 2 {CO}_{2} (g) + 2 H_{2} O (g)

(c)

C_{2} H_{4} (g) + 3 O_{2} (g) ⟶ 2 {CO}_{2} (g) + 2 H_{2} O (g)

(d)

Zn (s) + H_{2} {SO}_{4} (a q) ⟶ {ZnSO}_{4} (a q) + H_{2} (g)

(d)

Zn (s) + H_{2} {SO}_{4} (a q) ⟶ {ZnSO}_{4} (a q) + H_{2} (g)

(e)

2 K_{2} S_{2} O_{3} (s) + I_{2} (s) ⟶ K_{2} S_{4} O_{6} (s) + 2 KI (s)

(e)

2 K_{2} S_{2} O_{3} (s) + I_{2} (s) ⟶ K_{2} S_{4} O_{6} (s) + 2 KI (s)

(f)

3 Cu (s) + 8 {HNO}_{3} (a q) ⟶ 3 Cu {({NO}_{3})}_{2} (a q) + 2 NO (g) + 4 H_{2} O (l)

(f)

3 Cu (s) + 8 {HNO}_{3} (a q) ⟶ 3 Cu {({NO}_{3})}_{2} (a q) + 2 NO (g) + 4 H_{2} O (l)

Exercise 21問題 21

Complete and balance the following acid-base equations:

次の酸塩基反応式を完成させ、係数を合わせなさい。

(a) HCl gas reacts with solid Ca(OH)₂(s).

(a) HCl気体が固体のCa(OH)₂(s)と反応する。

(b) A solution of Sr(OH)₂ is added to a solution of HNO₃.

(b) Sr(OH)₂の水溶液をHNO₃の水溶液に加える。

Solution解き方

(a)

2 HCl (g) + Ca {(OH)}_{2} (s) ⟶ {CaCl}_{2} (s) + 2 H_{2} O (l);

(b)

Sr {(OH)}_{2} (a q) + 2 {HNO}_{3} (a q) ⟶ Sr {({NO}_{3})}_{2} (a q) + 2 H_{2} O (l)

(a)

2 HCl (g) + Ca {(OH)}_{2} (s) ⟶ {CaCl}_{2} (s) + 2 H_{2} O (l);

(b)

Sr {(OH)}_{2} (a q) + 2 {HNO}_{3} (a q) ⟶ Sr {({NO}_{3})}_{2} (a q) + 2 H_{2} O (l)

Exercise 22問題 22

Complete and balance the following acid-base equations:

次の酸塩基反応式を完成させ、係数を合わせなさい。

(a) A solution of HClO₄ is added to a solution of LiOH.

(a) HClO₄の水溶液をLiOHの水溶液に加える。

(b) Aqueous H₂SO₄ reacts with NaOH.

(b) H₂SO₄水溶液がNaOHと反応する。

Exercise 23問題 23

Complete and balance the following oxidation-reduction reactions, which give the highest possible oxidation state for the oxidized atoms.

次の酸化還元反応式を完成させ、係数を合わせなさい。酸化される原子は、取り得る最も高い酸化状態になる。

(a)

Al (s) + F_{2} (g) ⟶

(a)

Al (s) + F_{2} (g) ⟶

(b)

Al (s) + {CuBr}_{2} (a q) ⟶

(single displacement)

(b)

Al (s) + {CuBr}_{2} (a q) ⟶

（単置換）

(c)

P_{4} (s) + O_{2} (g) ⟶

(c)

P_{4} (s) + O_{2} (g) ⟶

(d)

Ca (s) + H_{2} O (l) ⟶

(products are a strong base and a diatomic gas)

(d)

Ca (s) + H_{2} O (l) ⟶

（生成物は強塩基と二原子分子の気体）

Solution解き方

(a)

2 Al (s) + 3 F_{2} (g) ⟶ 2 {AlF}_{3} (s);

(b)

2 Al (s) + 3 {CuBr}_{2} (a q) ⟶ 3 Cu (s) + 2 {AlBr}_{3} (a q);

(c)

P_{4} (s) + 5 O_{2} (g) ⟶ P_{4} O_{10} (s);

(d)

Ca (s) + 2 H_{2} O (l) ⟶ Ca {(OH)}_{2} (a q) + H_{2} (g)

(a)

2 Al (s) + 3 F_{2} (g) ⟶ 2 {AlF}_{3} (s);

(b)

2 Al (s) + 3 {CuBr}_{2} (a q) ⟶ 3 Cu (s) + 2 {AlBr}_{3} (a q);

(c)

P_{4} (s) + 5 O_{2} (g) ⟶ P_{4} O_{10} (s);

(d)

Ca (s) + 2 H_{2} O (l) ⟶ Ca {(OH)}_{2} (a q) + H_{2} (g)

Exercise 24問題 24

Complete and balance the following oxidation-reduction reactions, which give the highest possible oxidation state for the oxidized atoms.

次の酸化還元反応式を完成させ、係数を合わせなさい。酸化される原子は、取り得る最も高い酸化状態になる。

(a)

K (s) + H_{2} O (l) ⟶

(a)

K (s) + H_{2} O (l) ⟶

(b)

Ba (s) + HBr (a q) ⟶

(b)

Ba (s) + HBr (a q) ⟶

(c)

Sn (s) + I_{2} (s) ⟶

(c)

Sn (s) + I_{2} (s) ⟶

Exercise 25問題 25

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.

次の酸塩基中和反応の反応式を完成させ、係数を合わせなさい。水を溶媒として使う場合は、反応物と生成物を水溶液中のイオンとして書きなさい。使う反応物の量によっては、正解が複数ある場合もある。

(a)

Mg {(OH)}_{2} (s) + {HClO}_{4} (a q) ⟶

(a)

Mg {(OH)}_{2} (s) + {HClO}_{4} (a q) ⟶

(b)

{SO}_{3} (g) + H_{2} O (l) ⟶ (assume an excess of water and that the product dissolves)

(b)

{SO}_{3} (g) + H_{2} O (l) ⟶ （水は過剰で、生成物は溶けると仮定する）

(c)

SrO (s) + H_{2} {SO}_{4} (l) ⟶

(c)

SrO (s) + H_{2} {SO}_{4} (l) ⟶

Solution解き方

(a)

Mg {(OH)}_{2} (s) + 2 {HClO}_{4} (a q) ⟶ {Mg}^{2+} (a q) + 2 {ClO}_{4}^{−} (a q) + 2 H_{2} O (l);

(b)

{SO}_{3} (g) + 2 H_{2} O (l) ⟶ H_{3} O^{+} (a q) + {HSO}_{4}^{−} (a q),

(a solution of H₂SO₄); (c)

SrO (s) + H_{2} {SO}_{4} (l) ⟶ {SrSO}_{4} (s) + H_{2} O

(a)

Mg {(OH)}_{2} (s) + 2 {HClO}_{4} (a q) ⟶ {Mg}^{2+} (a q) + 2 {ClO}_{4}^{−} (a q) + 2 H_{2} O (l);

(b)

{SO}_{3} (g) + 2 H_{2} O (l) ⟶ H_{3} O^{+} (a q) + {HSO}_{4}^{−} (a q),

（H₂SO₄の水溶液）、(c)

SrO (s) + H_{2} {SO}_{4} (l) ⟶ {SrSO}_{4} (s) + H_{2} O

Exercise 26問題 26

When heated to 700–800 °C, diamonds, which are pure carbon, are oxidized by atmospheric oxygen. (They burn!) Write the balanced equation for this reaction.

純粋な炭素であるダイヤモンドは、700～800 °Cに加熱すると大気中の酸素によって酸化される（燃えるのである）。この反応について、係数のつり合った式を書きなさい。

Exercise 27問題 27

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?

軍では、フッ素が水素と爆発的に結合するときに非常に強い光を生じるレーザーの実験が行われている。この反応の、係数のつり合った式は何か。

Solution解き方

H_{2} (g) + F_{2} (g) ⟶ 2HF (g)

H_{2} (g) + F_{2} (g) ⟶ 2HF (g)

Exercise 28問題 28

Write the molecular, total ionic, and net ionic equations for the following reactions:

次の反応について、分子反応式、完全イオン反応式、正味のイオン反応式を書きなさい。

(a)

Ca {(OH)}_{2} (a q) + {HC}_{2} H_{3} O_{2} (a q) ⟶

(a)

Ca {(OH)}_{2} (a q) + {HC}_{2} H_{3} O_{2} (a q) ⟶

(b)

H_{3} {PO}_{4} (a q) + {CaCl}_{2} (a q) ⟶

(b)

H_{3} {PO}_{4} (a q) + {CaCl}_{2} (a q) ⟶

Exercise 29問題 29

Great Lakes Chemical Company produces bromine, Br₂, from bromide salts such as NaBr, in Arkansas brine by treating the brine with chlorine gas. Write a balanced equation for the reaction of NaBr with Cl₂.

グレートレイクス・ケミカル社は、アーカンソー州の塩水を塩素気体で処理し、その中のNaBrなどの臭化物塩から臭素Br₂を製造している。NaBrとCl₂の反応について、係数のつり合った式を書きなさい。

Solution解き方

2NaBr (a q) + {Cl}_{2} (g) ⟶ 2 NaCl (a q) + {Br}_{2} (l)

2NaBr (a q) + {Cl}_{2} (g) ⟶ 2 NaCl (a q) + {Br}_{2} (l)

Exercise 30問題 30

In a common experiment in the general chemistry laboratory, magnesium metal is heated in air to produce MgO. MgO is a white solid, but in these experiments it often looks gray, due to small amounts of Mg₃N₂, a compound formed as some of the magnesium reacts with nitrogen. Write a balanced equation for each reaction.

一般化学の実験でよく行う操作として、金属マグネシウムを空気中で加熱してMgOをつくるものがある。MgOは白色の固体であるが、この実験では灰色に見えることがよくある。これは、一部のマグネシウムが窒素と反応してできる化合物Mg₃N₂が少量混ざるためである。各反応について、係数のつり合った式を書きなさい。

Exercise 31問題 31

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 CO₂. (Hint: Water is one of the products.)

英語のヒント

水酸化リチウムは、有人宇宙船や潜水艦などの閉鎖環境で二酸化炭素を吸収するために使える。CO₂ 1 molにつきLiOH 2 molが関与する反応の式を書きなさい。（ヒント：生成物の一つは水である。）

Solution解き方

2 LiOH (a q) + {CO}_{2} (g) ⟶ {Li}_{2} {CO}_{3} (a q) + H_{2} O (l)

2 LiOH (a q) + {CO}_{2} (g) ⟶ {Li}_{2} {CO}_{3} (a q) + H_{2} O (l)

Exercise 32問題 32

Calcium propionate is sometimes added to bread to retard spoilage. This compound can be prepared by the reaction of calcium carbonate, CaCO₃, with propionic acid, C₂H₅CO₂H, which has properties similar to those of acetic acid. Write the balanced equation for the formation of calcium propionate.

英語のヒント

腐敗を遅らせるため、パンにプロピオン酸カルシウムを加えることがある。この化合物は、炭酸カルシウムCaCO₃と、酢酸に似た性質をもつプロピオン酸C₂H₅CO₂Hとの反応で調製できる。プロピオン酸カルシウムの生成について、係数のつり合った式を書きなさい。

Exercise 33問題 33

Complete and balance the equations of the following reactions, each of which could be used to remove hydrogen sulfide from natural gas:

天然ガスから硫化水素を除くのに使える、次の各反応の式を完成させ、係数を合わせなさい。

(a)

Ca {(OH)}_{2} (s) + H_{2} S (g) ⟶

(a)

Ca {(OH)}_{2} (s) + H_{2} S (g) ⟶

(b)

{Na}_{2} {CO}_{3} (a q) + H_{2} S (g) ⟶

(b)

{Na}_{2} {CO}_{3} (a q) + H_{2} S (g) ⟶

Solution解き方

(a)

Ca {(OH)}_{2} (s) + H_{2} S (g) ⟶ CaS (s) + 2 H_{2} O (l);

(b)

{Na}_{2} {CO}_{3} (a q) + H_{2} S (g) ⟶ {Na}_{2} S (a q) + {CO}_{2} (g) + H_{2} O (l)

(a)

Ca {(OH)}_{2} (s) + H_{2} S (g) ⟶ CaS (s) + 2 H_{2} O (l);

(b)

{Na}_{2} {CO}_{3} (a q) + H_{2} S (g) ⟶ {Na}_{2} S (a q) + {CO}_{2} (g) + H_{2} O (l)

Exercise 34問題 34

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 dihydrogen sulfate as the only product. Write the two equations which represent these reactions.

英語のヒント

硫化銅(II)は分子状酸素によって酸化され、気体の三酸化硫黄と固体の酸化銅(II)を生じる。続いて、この気体生成物が液体の水と反応し、唯一の生成物として液体の硫酸二水素を生じる。これらの反応を表す二つの式を書きなさい。

Exercise 35問題 35

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.

与えられた出発物質から次の各化合物を調製する反応について、係数のつり合った化学反応式を書きなさい。場合によっては、追加の反応物が必要である。

(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)

(a) 気体の分子状窒素から、二段階の過程で固体の硝酸アンモニウムをつくる（まず窒素をアンモニアに還元し、次に適切な酸でアンモニアを中和する）。

(b) gaseous hydrogen bromide from liquid molecular bromine via a one-step redox reaction

(b) 液体の分子状臭素から、一段階の酸化還元反応で気体の臭化水素をつくる。

(c) gaseous H₂S from solid Zn and S via a two-step process (first a redox reaction between the starting materials, then reaction of the product with a strong acid)

Solution解き方

(a) step 1:

N_{2} (g) + 3 H_{2} (g) ⟶ 2 {NH}_{3} (g),

step 2:

{NH}_{3} (g) + {HNO}_{3} (a q) ⟶ {NH}_{4} {NO}_{3} (a q) ⟶ {NH}_{4} {NO}_{3} (s) (after drying);

(b)

H_{2} (g) + {Br}_{2} (l) ⟶ 2 HBr (g);

(c)

Zn (s) + S (s) ⟶ ZnS (s)

and

ZnS (s) + 2 HCl (a q) ⟶ {ZnCl}_{2} (a q) + H_{2} S (g)

(a) 第1段階：

N_{2} (g) + 3 H_{2} (g) ⟶ 2 {NH}_{3} (g),

第2段階：

{NH}_{3} (g) + {HNO}_{3} (a q) ⟶ {NH}_{4} {NO}_{3} (a q) ⟶ {NH}_{4} {NO}_{3} (s) （乾燥後）；

(b)

H_{2} (g) + {Br}_{2} (l) ⟶ 2 HBr (g);

(c)

Zn (s) + S (s) ⟶ ZnS (s)

および

ZnS (s) + 2 HCl (a q) ⟶ {ZnCl}_{2} (a q) + H_{2} S (g)

Exercise 36問題 36

Calcium cyclamate Ca(C₆H₁₁NHSO₃)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 C₆H₁₁NHSO₃H 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.

英語のヒント

シクラミン酸カルシウムCa(C₆H₁₁NHSO₃)₂は、世界の多くの国で使われている人工甘味料であるが、米国では禁止されている。工業的には、酸C₆H₁₁NHSO₃Hを炭酸バリウムと反応させてバリウム塩に変え、硫酸で処理し（硫酸バリウムは極めて溶けにくい）、その後、水酸化カルシウムで中和することで精製できる。これらの反応について、係数のつり合った式を書きなさい。

Exercise 37問題 37

Complete and balance each of the following half-reactions (steps 2–5 in half-reaction method):

次の各半反応式を完成させ、係数を合わせなさい（半反応式法の手順2～5）。

(a)

{Sn}^{4+} (a q) ⟶ {Sn}^{2+} (a q)

(a)

{Sn}^{4+} (a q) ⟶ {Sn}^{2+} (a q)

(b)

{[Ag {({NH}_{3})}_{2}]}^{+} (a q) ⟶ Ag (s) + {NH}_{3} (a q)

(b)

{[Ag {({NH}_{3})}_{2}]}^{+} (a q) ⟶ Ag (s) + {NH}_{3} (a q)

(c)

{Hg}_{2} {Cl}_{2} (s) ⟶ Hg (l) + {Cl}^{−} (a q)

(c)

{Hg}_{2} {Cl}_{2} (s) ⟶ Hg (l) + {Cl}^{−} (a q)

(d)

H_{2} O (l) ⟶ O_{2} (g)

(in acidic solution)

(d)

H_{2} O (l) ⟶ O_{2} (g)

（酸性溶液中）

(e)

{IO}_{3}^{−} (a q) ⟶ I_{2} (s)

(in basic solution)

(e)

{IO}_{3}^{−} (a q) ⟶ I_{2} (s)

（塩基性溶液中）

(f)

{SO}_{3}^{2−} (a q) ⟶ {SO}_{4}^{2−} (a q)

(in acidic solution)

(f)

{SO}_{3}^{2−} (a q) ⟶ {SO}_{4}^{2−} (a q)

（酸性溶液中）

(g)

{MnO}_{4}^{−} (a q) ⟶ {Mn}^{2+} (a q)

(in acidic solution)

(g)

{MnO}_{4}^{−} (a q) ⟶ {Mn}^{2+} (a q)

（酸性溶液中）

(h)

{Cl}^{−} (a q) ⟶ {ClO}_{3}^{−} (a q)

(in basic solution)

(h)

{Cl}^{−} (a q) ⟶ {ClO}_{3}^{−} (a q)

（塩基性溶液中）

Solution解き方

(a)

{Sn}^{4+} (a q) + {2e}^{-} ⟶ {Sn}^{2+} (a q),

(b)

{[Ag {({NH}_{3})}_{2}]}^{+} (a q) + e^{-} ⟶ Ag (s) + 2 {NH}_{3} (a q);

(c)

{Hg}_{2} {Cl}_{2} (s) + 2 e^{-} ⟶ 2 Hg (l) + 2 {Cl}^{−} (a q);

(d)

2 H_{2} O (l) ⟶ O_{2} (g) + 4 H^{+} (a q) + 4 e^{-};

(e)

6 H_{2} O (l) + 2 {IO}_{3}^{−} (a q) + 10 e^{-} ⟶ I_{2} (s) + 12 {OH}^{−} (a q);

(f)

H_{2} O (l) + {SO}_{3}^{2−} (a q) ⟶ {SO}_{4}^{2−} (a q) + 2 H^{+} (a q) + 2 e^{-};

(g)

8 H^{+} (a q) + {MnO}_{4}^{−} (a q) + 5 e^{-} ⟶ {Mn}^{2+} (a q) + 4 H_{2} O (l);

(h)

{Cl}^{−} (a q) + 6 {OH}^{−} (a q) ⟶ Cl O_{3}^{−} (a q) + 3 H_{2} O (l) + 6 e^{-}

(a)

{Sn}^{4+} (a q) + {2e}^{-} ⟶ {Sn}^{2+} (a q),

(b)

{[Ag {({NH}_{3})}_{2}]}^{+} (a q) + e^{-} ⟶ Ag (s) + 2 {NH}_{3} (a q);

(c)

{Hg}_{2} {Cl}_{2} (s) + 2 e^{-} ⟶ 2 Hg (l) + 2 {Cl}^{−} (a q);

(d)

2 H_{2} O (l) ⟶ O_{2} (g) + 4 H^{+} (a q) + 4 e^{-};

(e)

6 H_{2} O (l) + 2 {IO}_{3}^{−} (a q) + 10 e^{-} ⟶ I_{2} (s) + 12 {OH}^{−} (a q);

(f)

H_{2} O (l) + {SO}_{3}^{2−} (a q) ⟶ {SO}_{4}^{2−} (a q) + 2 H^{+} (a q) + 2 e^{-};

(g)

8 H^{+} (a q) + {MnO}_{4}^{−} (a q) + 5 e^{-} ⟶ {Mn}^{2+} (a q) + 4 H_{2} O (l);

(h)

{Cl}^{−} (a q) + 6 {OH}^{−} (a q) ⟶ Cl O_{3}^{−} (a q) + 3 H_{2} O (l) + 6 e^{-}

Exercise 38問題 38

Complete and balance each of the following half-reactions (steps 2–5 in half-reaction method):

次の各半反応式を完成させ、係数を合わせなさい（半反応式法の手順2～5）。

(a)

{Cr}^{2+} (a q) ⟶ {Cr}^{3+} (a q)

(a)

{Cr}^{2+} (a q) ⟶ {Cr}^{3+} (a q)

(b)

Hg (l) + {Br}^{−} (a q) ⟶ {HgBr}_{4}^{2−} (a q)

(b)

Hg (l) + {Br}^{−} (a q) ⟶ {HgBr}_{4}^{2−} (a q)

(c)

ZnS (s) ⟶ Zn (s) + S^{2−} (a q)

(c)

ZnS (s) ⟶ Zn (s) + S^{2−} (a q)

(d)

H_{2} (g) ⟶ H_{2} O (l)

(in basic solution)

(d)

H_{2} (g) ⟶ H_{2} O (l)

（塩基性溶液中）

(e)

H_{2} (g) ⟶ H_{3} O^{+} (a q)

(in acidic solution)

(e)

H_{2} (g) ⟶ H_{3} O^{+} (a q)

（酸性溶液中）

(f)

{NO}_{3}^{−} (a q) ⟶ {HNO}_{2} (a q)

(in acidic solution)

(f)

{NO}_{3}^{−} (a q) ⟶ {HNO}_{2} (a q)

（酸性溶液中）

(g)

{MnO}_{2} (s) ⟶ {MnO}_{4}^{−} (a q)

(in basic solution)

(g)

{MnO}_{2} (s) ⟶ {MnO}_{4}^{−} (a q)

（塩基性溶液中）

(h)

{Cl}^{−} (a q) ⟶ {ClO}_{3}^{−} (a q)

(in acidic solution)

(h)

{Cl}^{−} (a q) ⟶ {ClO}_{3}^{−} (a q)

（酸性溶液中）

Exercise 39問題 39

Balance each of the following equations according to the half-reaction method:

半反応式法に従って、次の各反応式の係数を合わせなさい。

(a)

{Sn}^{2+} (a q) + {Cu}^{2+} (a q) ⟶ {Sn}^{4+} (a q) + {Cu}^{+} (a q)

(a)

{Sn}^{2+} (a q) + {Cu}^{2+} (a q) ⟶ {Sn}^{4+} (a q) + {Cu}^{+} (a q)

(b)

H_{2} S (g) + {Hg}_{2}^{2+} (a q) ⟶ H g (l) + S (s) (in acid)

(b)

H_{2} S (g) + {Hg}_{2}^{2+} (a q) ⟶ H g (l) + S (s) （酸性で）

(c)

{CN}^{−} (a q) + {ClO}_{2} (a q) ⟶ {CNO}^{−} (a q) + {Cl}^{−} (a q) (in acid)

(c)

{CN}^{−} (a q) + {ClO}_{2} (a q) ⟶ {CNO}^{−} (a q) + {Cl}^{−} (a q) （酸性で）

(d)

{Fe}^{2+} (a q) + {Ce}^{4+} (a q) ⟶ {Fe}^{3+} (a q) + {Ce}^{3+} (a q)

(d)

{Fe}^{2+} (a q) + {Ce}^{4+} (a q) ⟶ {Fe}^{3+} (a q) + {Ce}^{3+} (a q)

(e)

HBrO (a q) ⟶ {Br}^{−} (a q) + O_{2} (g) (in acid)

(e)

HBrO (a q) ⟶ {Br}^{−} (a q) + O_{2} (g) （酸性で）

Solution解き方

(a)

{Sn}^{2+} (a q) + 2 {Cu}^{2+} (a q) ⟶ {Sn}^{4+} (a q) + 2 {Cu}^{+} (a q);

(b)

H_{2} S (g) + {Hg}_{2}^{2+} (a q) + 2 H_{2} O (l) ⟶ 2 Hg (l) + S (s) + 2 H_{3} O^{+} (a q);

(c)

5 {CN}^{−} (a q) + 2 {ClO}_{2} (a q) + 3 H_{2} O (l) ⟶ 5 {CNO}^{−} (a q) + 2 {Cl}^{−} (a q) + 2 H_{3} O^{+} (a q);

(d)

{Fe}^{2+} (a q) + {Ce}^{4+} (a q) ⟶ {Fe}^{3+} (a q) + {Ce}^{3+} (a q);

(e)

2 HBrO (a q) + 2 H_{2} O (l) ⟶ 2 H_{3} O^{+} (a q) + 2 {Br}^{−} (a q) + O_{2} (g)

(a)

{Sn}^{2+} (a q) + 2 {Cu}^{2+} (a q) ⟶ {Sn}^{4+} (a q) + 2 {Cu}^{+} (a q);

(b)

H_{2} S (g) + {Hg}_{2}^{2+} (a q) + 2 H_{2} O (l) ⟶ 2 Hg (l) + S (s) + 2 H_{3} O^{+} (a q);

(c)

5 {CN}^{−} (a q) + 2 {ClO}_{2} (a q) + 3 H_{2} O (l) ⟶ 5 {CNO}^{−} (a q) + 2 {Cl}^{−} (a q) + 2 H_{3} O^{+} (a q);

(d)

{Fe}^{2+} (a q) + {Ce}^{4+} (a q) ⟶ {Fe}^{3+} (a q) + {Ce}^{3+} (a q);

(e)

2 HBrO (a q) + 2 H_{2} O (l) ⟶ 2 H_{3} O^{+} (a q) + 2 {Br}^{−} (a q) + O_{2} (g)

Exercise 40問題 40

Balance each of the following equations according to the half-reaction method:

半反応式法に従って、次の各反応式の係数を合わせなさい。

(a)

Zn (s) + {NO}_{3}^{−} (a q) ⟶ {Zn}^{2+} (a q) + N_{2} (g) (in acid)

(a)

Zn (s) + {NO}_{3}^{−} (a q) ⟶ {Zn}^{2+} (a q) + N_{2} (g) （酸性で）

(b)

Zn (s) + {NO}_{3}^{−} (a q) ⟶ {Zn}^{2+} (a q) + {NH}_{3} (a q) (in base)

(b)

Zn (s) + {NO}_{3}^{−} (a q) ⟶ {Zn}^{2+} (a q) + {NH}_{3} (a q) （塩基性で）

(c)

CuS (s) + {NO}_{3}^{−} (a q) ⟶ {Cu}^{2+} (a q) + S (s) + NO (g) (in acid)

(c)

CuS (s) + {NO}_{3}^{−} (a q) ⟶ {Cu}^{2+} (a q) + S (s) + NO (g) （酸性で）

(d)

{NH}_{3} (a q) + O_{2} (g) ⟶ {NO}_{2} (g) (gas phase)

(d)

{NH}_{3} (a q) + O_{2} (g) ⟶ {NO}_{2} (g) （気相）

(e)

H_{2} O_{2} (a q) + {MnO}_{4}^{−} (a q) ⟶ {Mn}^{2+} (a q) + O_{2} (g) (in acid)

(e)

H_{2} O_{2} (a q) + {MnO}_{4}^{−} (a q) ⟶ {Mn}^{2+} (a q) + O_{2} (g) （酸性で）

(f)

{NO}_{2} (g) ⟶ {NO}_{3}^{−} (a q) + {NO}_{2}^{−} (a q) (in base)

(f)

{NO}_{2} (g) ⟶ {NO}_{3}^{−} (a q) + {NO}_{2}^{−} (a q) （塩基性で）

(g)

{Fe}^{3+} (a q) + I^{−} (a q) ⟶ {Fe}^{2+} (a q) + I_{2} (a q)

(g)

{Fe}^{3+} (a q) + I^{−} (a q) ⟶ {Fe}^{2+} (a q) + I_{2} (a q)

Exercise 41問題 41

Balance each of the following equations according to the half-reaction method:

半反応式法に従って、次の各反応式の係数を合わせなさい。

(a)

{MnO}_{4}^{−} (a q) + {NO}_{2}^{−} (a q) ⟶ {MnO}_{2} (s) + {NO}_{3}^{−} (a q) (in base)

(a)

{MnO}_{4}^{−} (a q) + {NO}_{2}^{−} (a q) ⟶ {MnO}_{2} (s) + {NO}_{3}^{−} (a q) （塩基性で）

(b)

{MnO}_{4}^{2−} (a q) ⟶ {MnO}_{4}^{−} (a q) + {MnO}_{2} (s) (in base)

(b)

{MnO}_{4}^{2−} (a q) ⟶ {MnO}_{4}^{−} (a q) + {MnO}_{2} (s) （塩基性で）

(c)

{Br}_{2} (l) + {SO}_{2} (g) ⟶ {Br}^{−} (a q) + {SO}_{4}^{2−} (a q) (in acid)

(c)

{Br}_{2} (l) + {SO}_{2} (g) ⟶ {Br}^{−} (a q) + {SO}_{4}^{2−} (a q) （酸性で）

Solution解き方

(a)

2 {MnO}_{4}^{−} (a q) + {3NO}_{2}^{−} (a q) + H_{2} O (l) ⟶ 2 {MnO}_{2} (s) + 3 {NO}_{3}^{−} (a q) + 2 {OH}^{−} (a q);

(b)

3 {MnO}_{4}^{2−} (a q) + 2 H_{2} O (l) ⟶ 2 {MnO}_{4}^{−} (a q) + 4 {OH}^{−} (a q) + {MnO}_{2} (s) (in base);

(c)

{Br}_{2} (l) + {SO}_{2} (g) + 2 H_{2} O (l) ⟶ 4 H^{+} (a q) + 2 {Br}^{−} (a q) + {SO}_{4}^{2−} (a q)

(a)

2 {MnO}_{4}^{−} (a q) + {3NO}_{2}^{−} (a q) + H_{2} O (l) ⟶ 2 {MnO}_{2} (s) + 3 {NO}_{3}^{−} (a q) + 2 {OH}^{−} (a q);

(b)

3 {MnO}_{4}^{2−} (a q) + 2 H_{2} O (l) ⟶ 2 {MnO}_{4}^{−} (a q) + 4 {OH}^{−} (a q) + {MnO}_{2} (s) （塩基性で）;

(c)

{Br}_{2} (l) + {SO}_{2} (g) + 2 H_{2} O (l) ⟶ 4 H^{+} (a q) + 2 {Br}^{−} (a q) + {SO}_{4}^{2−} (a q)

acid

酸

substance that produces H₃O⁺ when dissolved in water

水に溶けるとH₃O⁺を生じる物質。

acid-base reaction

酸塩基反応

reaction involving the transfer of a hydrogen ion between reactant species

反応する化学種の間で水素イオンが移る反応。

base

塩基

substance that produces OH⁻ when dissolved in water

水に溶けるとOH⁻を生じる物質。

combustion reaction

燃焼反応

vigorous redox reaction producing significant amounts of energy in the form of heat and, sometimes, light

熱、場合によっては光の形で、多量のエネルギーを生じる激しい酸化還元反応。

half-reaction

半反応式

an equation that shows whether each reactant loses or gains electrons in a reaction.

反応の際に各反応物が電子を失うか、受け取るかを示す式。

insoluble

不溶性

of relatively low solubility; dissolving only to a slight extent

溶解度が比較的低いこと。わずかしか溶けないこと。

neutralization reaction

中和反応

reaction between an acid and a base to produce salt and water

酸と塩基が反応して、塩と水を生じる反応。

oxidation

酸化

process in which an element’s oxidation number is increased by loss of electrons

電子を失うことにより、元素の酸化数が増加する過程。

oxidation-reduction reaction

酸化還元反応

(also, redox reaction) reaction involving a change in oxidation number for one or more reactant elements

レドックス反応ともいう。反応物を構成する一種類以上の元素の酸化数が変化する反応。

oxidation number

酸化数

(also, oxidation state) the charge each atom of an element would have in a compound if the compound were ionic

酸化状態ともいう。化合物がイオン性であったとしたとき、その中である元素の各原子がもつであろう電荷。

oxidizing agent

酸化剤

(also, oxidant) substance that brings about the oxidation of another substance, and in the process becomes reduced

oxidantともいう。ほかの物質を酸化させ、その過程で自らは還元される物質。

precipitate

沈殿

insoluble product that forms from reaction of soluble reactants

可溶性の反応物の反応によって生じる、不溶性の生成物。

precipitation reaction

沈殿反応

reaction that produces one or more insoluble products; when reactants are ionic compounds, sometimes called double-displacement or metathesis

一種類以上の不溶性生成物を生じる反応。反応物がイオン化合物である場合、複置換反応やメタセシス反応と呼ばれることもある。

reduction

還元

process in which an element’s oxidation number is decreased by gain of electrons

電子を受け取ることにより、元素の酸化数が減少する過程。

reducing agent

還元剤

(also, reductant) substance that brings about the reduction of another substance, and in the process becomes oxidized

reductantともいう。ほかの物質を還元させ、その過程で自らは酸化される物質。

salt

塩

ionic compound that can be formed by the reaction of an acid with a base that contains a cation and an anion other than hydroxide or oxide

酸と塩基の反応で形成できるイオン化合物で、陽イオンと、水酸化物イオンや酸化物イオン以外の陰イオンを含むもの。

single-displacement reaction

単置換反応

(also, replacement) redox reaction involving the oxidation of an elemental substance by an ionic species

置換反応ともいう。イオン性化学種によって単体が酸化される酸化還元反応。

soluble

可溶性

of relatively high solubility; dissolving to a relatively large extent

溶解度が比較的高いこと。比較的多く溶けること。

solubility

溶解度

the extent to which a substance may be dissolved in water, or any solvent

物質が水、またはその他の溶媒にどの程度溶けるかを表すもの。

strong acid

強酸

acid that reacts completely when dissolved in water to yield hydronium ions

水に溶けると完全に反応し、ヒドロニウムイオンを生じる酸。

strong base

強塩基

base that reacts completely when dissolved in water to yield hydroxide ions

水に溶けると完全に反応し、水酸化物イオンを生じる塩基。

weak acid

弱酸

acid that reacts only to a slight extent when dissolved in water to yield hydronium ions

水に溶けるとわずかだけ反応し、ヒドロニウムイオンを生じる酸。

weak base

弱塩基

base that reacts only to a slight extent when dissolved in water to yield hydroxide ions

水に溶けるとわずかだけ反応し、水酸化物イオンを生じる塩基。