Some Types of Chemical Reactions

1. 6 Some Types of Chemical Reactions

2. Outline 1. Aqueous Solutions 水溶液: An Introduction 2. Reactions in Aqueous Solutions Naming Some Inorganic Compounds 3. Naming Binary Compounds二元化合物的命名 4. Naming Ternary Acids and Their Salts三元酸的命名 Classifying Chemical Reactions 5. Oxidation-Reduction Reactions: An Introduction 6. Combination Reactions 化合反應 7. Decomposition Reactions 分解反應 8. Displacement Reactions分解反應 9. Metathesis Reactions 複分解反應 10. Gas-Formation Reactions 11. Summary of Reaction Types

3. Aqueous Solutions: An Introduction Electrolytesand Extent of Ionization電解質及電解游離程度 • Electrolytes are substances whose aqueous solutions conduct electric current凡化合物溶於水能導電的物質即稱電解質 • Nonelectrolytes – solutes that do not conduct electricity in water 非電解質 • Weak electrolytes: conduct electricity poorly in dilute aqueous current 弱電解質:導電性較差 • Strong electrolytes: conduct electricity well in dilute aqueous current 強電解質:導電性較好 • The strength of a electrolyte depends on the number of ions in solution, and also on the charges on these ions 導電性的強度取決於溶液的離子數目及離子的電荷

4. Nonelectrolytes Weak electrolytes strong electrolytes

5. Aqueous Solutions: An Introduction • Nonelectrolytes – solutes that do not conduct electricity in water • C2H5OH - ethanol • C6H12O6 – glucose 葡萄糖 (blood sugar) • C12H22O11 – sucrose蔗糖 • (table sugar) H H C CH H C H O H OH H C C C C OH HO HO H

6. Aqueous Solutions: An Introduction • The reason nonelectrolytes do not conduct electricity is because they do not form ions in solution. • ions conduct electricity in solution Acid: a substance that produces hydrogen ions, H+, in aqueous solutions Base: a substance that produces hydroxide ions, OH-, in aqueous solutions Salt: a compound that contains a cation other than H+, and an anion other than hydroxide ion, OH- ,or oxide ion, O2-

7. 7

8. Aqueous Solutions: An Introduction • Classification of solutes • strong electrolytes強電解質- conduct electricityextremely well in dilute aqueous solutions • Examples of strong electrolytes • HCl, HNO3, etc. • strong soluble acids • NaOH, KOH, etc. • strong soluble bases • NaCl, KBr, etc. • soluble ionic salts • ionize in water essentially 100% 檸檬酸

9. Aqueous Solutions: An Introduction • Classification of solutes • weak electrolytes - conduct electricity poorly in dilute aqueous solutions • CH3COOH, (COOH)2 • weak acids • NH3, Fe(OH)3 • weak bases • some soluble covalent salts • ionize in water much less than 100%

10. HCl(g) H+(aq) + Cl-(aq) HNO3 + H2O H3O+(aq) + NO-3(aq) Aqueous Solutions: An Introduction Strong and Weak Acids 強酸及弱酸 • Acids are substances that generate H+ in aqueous solutions. • Strong acids ionize 100% in water. 100% 100% H2O HNO3 H+(aq) + NO-3(aq)

11. Aqueous Solutions: An Introduction strong acids--ionize almost 100% Table 6-1 氫氯酸 氫溴酸 氫碘酸 硝酸 過氯酸 氯酸 硫酸

12. Aqueous Solutions: An Introduction Weak acids--Typically ionize 10% or less! Table 6-2 氫氟酸 醋酸 氰化氫 亞硝酸 碳酸 亞硫酸 磷酸 草酸

13. Aqueous Solutions: An Introduction Organic acid 有機酸 • Contain the carboxylate group, ―COOH • Most organic acids are weak • ― COO- and H+ • Naturally occurring organic weak acid • Tartaric acid (grapes) 酒石酸 • Lactic acid (sour milk) 乳酸 • Formic acid (ants) 甲酸或稱蟻酸 Inorganic Acid 無機酸 • Often called mineral acids 礦物酸 • Contain Carbon but considered to be inorganic acid • Carbonic acid, H2CO3 碳酸 • Hydrocyanic acid, HCN 氰化氫

14. Example 6-1 Strong and Weak Acid In the following lists of common acids, which are strong and which are weak? (a) H3PO4, HCl, H2CO3, HNO3 (b) HClO4, H2SO4, HClO, HF. (a) HCl, HNO3are strong acids H3PO4, H2CO3 are weak acids (b) HClO4, H2SO4, are strong acids HClO, HF are weak acids Exercise 5, 7

15. Aqueous Solutions: An Introduction Reversible Reactions可逆反應 • Strong acid : the ionization of HCl in water is nearly complete • one direction • All weak inorganic acids ionize reversibly or in equilibrium reactions. • This is why they ionize less than 100%. • Correct chemical symbolism for equilibrium reactions CH3COOH (aq) CH3COO-(aq) + H+(aq) Reversible Reactions 可逆反應

16. Aqueous Solutions: An Introduction Strong Bases, Insoluble Bases, and Weak Bases 強鹼, 不可溶鹼及弱鹼 • Strong Bases 強鹼 • Characteristic of common inorganic bases is that they produce OH- ions in solution. • Similarly to strong acids, strong bases ionize 100% in water. NaOHNa+(aq) + OH-(aq) H2O H2O Ba(OH)2Ba+2(aq) + 2OH-(aq)

17. Aqueous Solutions: An Introduction Table 6-2 氫氧化鋰 氫氧化鈉 氫氧化鈣 氫氧化鉀 氫氧化鍶 氫氧化銣 氫氧化銫 氫氧化鋇 Notice that they are all hydroxides of IA and IIA metals

18. Aqueous Solutions: An Introduction Strong Bases, InsolubleBases, and Weak Bases • Insoluble bases • Ionic compounds that are insoluble in water, consequently, not very basic • Cu(OH)2, Zn(OH)2, Fe(OH)2氫氧化亞鐵, Fe(OH)3 • Weak bases • are covalent compounds that ionize slightly in water. • Ammonia is most common weak base-- NH3 • Closely related N-containing compounds, the amines • Methylamine CH3NH2甲胺 • Caffeine 咖啡因 NH3(aq) + H2O(l) NH4+(aq) + OH-(aq)

19. Example 6-2 Classifying Bases From the following lists, choose (i) the strong bases, (ii) the insoluble bases, and (iii) the weak bases. (a) NaOH, Cu(OH)2, Pb(OH)2, Ba(OH)2 (b) Fe(OH)3, KOH, Mg(OH)2, Sr(OH)2, NH3 (a) (i)The strong bases: NaOH, Ba(OH)2 (ii)The insoluble bases: Cu(OH)2, Pb(OH)2 (b) (i)The strong bases: KOH, Sr(OH)2 (ii)The insoluble bases: Fe(OH)3, Mg(OH)2 (iii)The weak bases: NH3 Exercise 8, 10

20. Aqueous Solutions: An Introduction Solubility 溶解度Guidelines for Compounds in Aqueous Solutions • It is very important that you know these guidelines and how to apply them in reactions. • Common inorganic acids and low-molecular-weight organic acidsare water soluble • All common compounds of the Group IA metal ions and the ammonium ion are water soluble. • Li+, Na+, K+,Rb+, Cs+,and NH4+

21. Aqueous Solutions: An Introduction • Common nitrates, acetates, chlorates, and perchlorates are water soluble • NO3-, CH3COO-, ClO3-,and ClO4- • Common chlorides氯化物 are water soluble • Exceptions – AgCl, Hg2Cl2,& PbCl2(例外) • Common bromides and iodides behave similarly to chlorides. • Common fluorides are water soluble. • Exceptions – MgF2, CaF2, SrF2, BaF2, and PbF2 硝酸根 醋酸根 氯酸根 過氯酸根

22. Aqueous Solutions: An Introduction • Common sulfates are water soluble • Exceptions – PbSO4, BaSO4, & HgSO4 • Moderately soluble – CaSO4, SrSO4,& Ag2SO4 • Commonmetal hydroxides are water insoluble • Exceptions – LiOH, NaOH, KOH, RbOH & CsOH (IA metal hydroxides)

23. Aqueous Solutions: An Introduction • Commoncarbonates, phosphates, and arsenates are water insoluble 碳酸鹽,磷酸鹽及砷酸鹽 • CO32-, PO43-, & AsO43- • Exceptions- IA metals and NH4+ Ba(CO3)2 is moderately soluble • Moderately soluble – MgCO3 • Common sulfides (S2-)are water insoluble • Exceptions – IA metals and NH4+ plus IIA metals

24. Aqueous Solutions: An Introduction Table 6-4 Insoluble soluble

25. Example 6-3 Solubility of Some Common Ionic Salt • From the following compounds, choose (a) those that are likely to be soluble in water and (b) those that are likely to be insoluble: NaBr, Cu(OH)2, PbCl2, AgI, Fe2O3, Mg(NO3)2, (NH4)2SO4 • The soluble compound: • NaBr, Mg(NO3)2, (NH4)2SO4 • (b)The insoluble compound: • Cu(OH)2, PbCl2, AgI, Fe2O3 Exercise 14, 16

26. Reactions in Aqueous Solutions There are three ways to write reactions in aqueous solutions. • Molecular equation 分子方程式 • Show all reactants & products in molecular or ionic form (more active metal replaces the compound) Cu(s) + 2AgNO3(aq) Cu(NO3)2 (aq) + 2Ag(s) Soluble ionic compounds Zn(s) + CuSO4(aq) ZnSO4(aq) +Cu(s)

27. Reactions in Aqueous Solutions There are three ways to write reactions in aqueous solutions. • Total ionic equation 完全離子方程式 • Show the ions and molecules as they exist in solution NO3- ions do not participate in the reaction They do not change  Spectator ions旁觀離子 Zn(s) + Cu2+ (aq)+SO42-(aq) Zn2+(aq)+SO42-(aq) +Cu(s) 2[Ag+ (s) +NO3- (aq)]+ Cu2+(aq)1Ag(s) +[Cu2+(aq)+2NO3-(aq) ]

28. Reactions in Aqueous Solutions There are three ways to write reactions in aqueous solutions. • Net ionic equation 淨離子方程式 • Shows ions that participate in reaction and removes spectator ions旁觀離子 Zn(s) + Cu2+ (aq)+SO42-(aq) Zn2+(aq)+SO42-(aq) +Cu(s) 2Ag+ (s) + Cu2+(aq) 2Ag(s) +Cu2+(aq) 2[Ag+ (s) +NO3- (aq)]+ Cu2+(aq) 2Ag(s) +[Cu2+(aq)+2NO3-(aq) ] Zn(s) + Cu2+(aq) Zn2+(aq)+Cu(s)

29. Reactions in Aqueous Solutions • In the total and net ionic equations the only common substances that should be written as ions are: • Strong acids • Strong bases • Soluble ionic salts

30. Reactions in Aqueous Solutions Table 6-5

31. Naming Some Inorganic Compounds無機化合物的命名 IUPAC國際純粹與應用化學聯合會 • Binary compounds (二元化合物) are made of two elements. • metal + nonmetal = ionic compound (離子化合物) • nonmetal + nonmetal = covalent compound (共價化合物 ) • Name the more metallic element first. • Use the element’s name. • Name the less metallic element second. • Add the suffix “ide” to the element’s stem. (字尾加上ide )

32. Table 6-6 陽離子 陰離子

34. Naming Some Inorganic Compounds • Nonmetal Stems ElementStem Boron (B) bor Carbon (C) carb Silicon (Si) silic Nitrogen (N) nitr Phosphorus (P) phosph Arsenic (As) arsen Antimony(Sb) antimon ElementStem Oxygen (O) ox Sulfur (S) sulf Selenium (Se) selen Tellurium (Te) tellur Hydrogen (H) hydr Fluorine (F) fluor Chlorine (Cl) chlor Bromine (Br) brom Iodine (I) iod

35. Naming Some Inorganic Compounds • Binary Ionic Compounds are made of a metal cationand a nonmetal anion. • Cation named first • Anion named second lithium bromide magnesium chloride lithium sulfide aluminum oxide sodium phosphide magnesium nitride Notice that binary ionic compounds with metals having one oxidation state (representative metals) do not use prefixes or Roman numerals. LiBr MgCl2 Li2S Al2O3 Na3P Mg3N2

36. Naming Some Inorganic Compounds • Binary ionic compounds containing metals that exhibit more than one oxidation state • Metals exhibiting multiple oxidation states are: • most of the transition metals • metals in groups 3A (except Al), 4A, & 5A

37. Naming Some Inorganic Compounds • There are two methods to name these compounds. • Older method • add suffix “ic” to element’s Latin name for higher oxidation state • add suffix “ous” to element’s Latin name for lower oxidation state • Modern method • use Roman numerals in parentheses to indicate metal’s oxidation state

38. Naming Some Inorganic Compounds Old System ferrous bromide ferric bromide stannous oxide stannic oxide titanous chloride Titanic chloride does not work Modern System Iron (II) bromide Iron (III) bromide Tin (II) oxide Tin (IV) oxide Titanium (II) chloride Titanium (III) chloride Titanium (IV) chloride Compound FeBr2+2 FeBr3+3 SnO +2 SnO2 +4 TiCl2 +2 TiCl3 +3 TiCl4+4

39. Naming Some Inorganic Compounds Pseudobinary ionic compounds • There are three polyatomic ions that commonly form binary ionic compounds. • OH- hydroxide • CN- cyanide • NH4+ ammonium Pseudo = false 假的

40. Naming Some Inorganic Compounds Use binary ionic compound naming system. potassium hydroxide barium hydroxide aluminum hydroxide iron (II) hydroxide iron (III) hydroxide barium cyanide ammonium sulfide ammonium cyanide copper (II) hydroxide KOH Ba(OH)2 Al(OH)3 Fe(OH)2 Fe(OH)3 Ba(CN)2 (NH4)2S NH4CN Cu(OH)2

41. Naming Some Inorganic Compounds • Binary acids arebinary compounds consisting of hydrogen and a nonmetal. • Compounds are usually gases at room temperature and pressure. • Nomenclature for the gaseous compounds is hydrogen (stem)ide. • When the compounds are dissolved in water they form acidic solutions. • Nomenclature for the acidic solutions is hydro (stem)ic acid. Formula HCl HF H2S HCN Name of compound hydrogen chloride hydrogen fluoride hydrogen sulfide hydrogen cyanide Name of Aqueous solution hydrochloric acid, HCl(aq) hydrofluoric acid, HF(aq) hydrosulfuric acid, H2S(aq) Hydrocyanic acid, HCN(aq)

42. Naming Some Inorganic Compounds • Binary covalent molecular compounds composed of two nonmetals other than hydrogen • Nomenclature must include prefixes that specify the number of atoms of each element in the compound. • Use the minimum number of prefixes necessary to specify the compound. • Frequently drop the prefix mono-1 2di5penta8 oct 3tri 6hexa9 nona 4 tetra 7 hepta10deca

43. Naming Some Inorganic Compounds Name carbon monoxide carbon dioxide sulfur trioxide oxygen difluoride tetraphosphorus hexoxide tetraphosphorus decoxide Formula CO CO2 SO3 OF2 P4O6 P4O10

44. Naming Some Inorganic Compounds • The oxides of nitrogen illustrate why covalent compounds need prefixes and ionic compounds do not. • FormulaOld NameModern Name • N2O nitrous oxide dinitrogen monoxide • NO nitric oxide nitrogen monoxide • N2O3 nitrogen trioxide dinitrogen trioxide • NO2 nitrogen dioxide nitrogen dioxide • N2O4 nitrogen tetroxide dinitrogen tetroxide • N2O5 nitrogen pentoxide dinitrogen pentoxide

45. Naming Some Inorganic Compounds • Ternary Acids and Their Salts are made ofthree elements. • The elements are H, O, & a nonmetal. • Two of the compounds are chosen as the basis for the nomenclature system. • Higher oxidation state for nonmetal is named (stem)ic acid. • Lower oxidation state for nonmetal is named (stem)ous acid • Salts are named based on the acids. • Anions of -ic acids make “ate” salts. • Anions of -ous acids make “ite” salts.

46. Naming Some Inorganic Compounds Table 6-7

47. Naming Some Inorganic Compounds • Salts are formed by the reaction of the acid with a strong base. AcidSalt HNO2 NaNO2 nitrous acid sodium nitrite HNO3 NaNO3 nitric acid sodium nitrate H2SO3 Na2SO3 sulfurous acid sodium sulfite H2SO4 Na2SO4 sulfuric acid sodium sulfate HClO2 NaClO2 chlorous acid sodium chlorite HClO3 NaClO3 chloric acidsodium chlorate

48. Naming Some Inorganic Compounds • There are two other possible acid and salt combinations. • Acids that have a higher oxidation state than the “ic” acid are given the prefix “per”. • These acids and salts will have one more O atom than the “ic” acid. • Acids that have a lower oxidation state than the “ous” acid are given the prefix “hypo”. • These acids and salts will have one less O atom than the “ous” acid.

49. Naming Some Inorganic Compounds • Illustrate this series of acids and salts with the Cl ternary acids and salts. AcidNa Salt HClO NaClO hypochlorous acid sodium hypochlorite HClO2 NaClO2 chlorous acid sodium chlorite HClO3 NaClO3 chloric acid sodium chlorate HClO4 NaClO4 perchloric acid sodium perchlorate

50. Naming Some Inorganic Compounds • Acidic Salts are made from ternary acids that retain one or more of their acidic hydrogen atoms. • Made from acid base reactions where there is an insufficient amount of base to react with all of the hydrogen atoms. • Old system used the prefix “bi” to denote the hydrogen atom. • Modern system uses prefixes and the word hydrogen.