1. Chapter Four Ionic Compounds Fundamentals of General, Organic & Biological Chemistry 4th Edition Mohammed Hashmat Ali Southeast Missouri State University  2003 Prentice Hall, Inc.

2. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 2 Sodium reacts explosively with water. © 2003 John Wiley and Sons Publishers Courtesy OPC Inc. Demo

3. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 3 The vigorous reaction of sodium with chlorine. © 2003 John Wiley and Sons Publishers Courtesy Ken Karp Demo

4. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 4 Common table salt, the product of the reaction of sodium with chlorine. © 2003 John Wiley and Sons Publishers Courtesy USDA

5. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 5 Figure 2.12: Names, symbols, electron structures, and compositions of nuclei of the first 10 elements. © 2003 John Wiley and Sons Publishers

6. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 6  The stability of the noble gases is associated with 8 valence electrons (He has 2). Ne 2, 8 Ar2, 8, 8 Kr2, 8, 18, 8  Atoms can become more stable by acquiring an octet (8 electrons) in the outer shell. Octet Rule

7. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 7 Figure 3.3: The reaction of sodium and chlorine to produce sodium chloride. © 2003 John Wiley and Sons Publishers

8. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 8  The valence electrons are the electrons in the outer shell.  The electrons in the outer shell have the most contact with other atoms and strongly influence the chemical properties of atoms. Valence Electrons

9. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 9 Number of Valence Electrons For Group A elements, the number of valence electrons is the number of electrons in the s and p subshells of the outer shell. In the electron configuration for phosphorus, there are 5 valence electrons in the s and p subshells with the highest number. 5 valence electrons P Group 5A 1s 2 2s 2 2p 6 3s 2 3p 3

10. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 10 Valence Electrons for Groups

11. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 11 State the number of valence electrons for each. A. Magnesium 1) 22) 63) 8 B. Oxygen 1) 22) 43) 6 C. Potassium 1) 12) 23) 7 Learning Check

12. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 12 State the number of valence electrons for each. A. Magnesium 1) 2 Group 2A 1s 2 2s 2 2p 6 3s 2 B. Oxygen 3) 6Group 6A 1s 2 2s 2 2p 4 C. Potassium 1) 1Group 1A 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 Solution

13. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 13 Electron Dot Structure An electron-dot structure is a convenient way to represent the valence electrons. For example, the two valence electrons for magnesium are placed as single dots on any two sides of the Mg symbol.

14. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 14 Electron-Dot Structures Dot structures are used for Group A elements. The valence electrons are placed on the sides of the symbol of an element.

15. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 15 A. X is the electron dot formula for 1) Na2) K3) Al B. X is the electron dot formula of 1) B2) N3) P Learning Check

16. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 16 A. X is the electron dot formula for 1) Na2) K B. X i s the electron dot formula of 2) N3) P Solution

17. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 17  The stability of the noble gases is associated with 8 valence electrons (He has 2). Ne 2, 8 Ar2, 8, 8 Kr2, 8, 18, 8  Atoms can become more stable by acquiring an octet (8 electrons) in the outer shell. Octet Rule

18. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 18 Fig 3.2 The periodic table

19. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 19 Ionization Energy Ionization energy is the energy it takes to remove a valence electron. Metals have lower ionization energies and nonmetals have higher ionization energies.

20. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 20 Halogens: Large ionization energy – electron not easily lost; Large electron affinity – electron easily gained – formation of anion is favored. Fig 4.1 Relative ionization energies (red) and electron affinities (blue) for elements in the first four rows of the periodic table.

21. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 21  Metals acquire octets by losing valence electrons.  The loss of electrons converts an atom to an ion that has the electron configuration of the nearest noble gas.  Metals form positive ions because they have fewer electrons than protons. Group 1A metals  ion 1+ Group 2A metals  ion 2+ Group 3A metals  ion 3+ Metals Form Positive Ions

22. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 22 Give the ionic charge for each ion. A. 12 p + and 10 e - 1) 02) 2+3) 2- B. 50p + and 46 e - 1) 2+2) 4+3) 4- C. 15 p + and 18e - 1) 3+ 2) 3-3) 5- Learning Check

23. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 23 Give the ionic charge for each ion. A. 12 p + and 10 e - 2) 2+ B. 50p + and 46 e - 2) 4+ C. 15 p + and 18e - 2) 3- Solution

24. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 24 Sodium forms an octet by losing its one valence electron. Na  – e   Na + 1s 2 2s 2 2p 6 3s 1 1s 2 2s 2 2p 6 (= Ne) A positive ion forms with a +1 charge. Sodium atom Sodium ion 11 p + 11 e - 10 e - 0 1 + Formation of a Sodium Ion, Na +

25. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 25 Magnesium forms an octet by losing its two valence electrons. Magnesium atom Magnesium ion  Mg  – 2e   Mg 2+ 1s 2 2s 2 2p 6 3s 2 1s 2 2s 2 2p 6 (= Ne) A positive ion forms with a +2 charge. 12 p + 12 p + 12 e- 10 e - 0 2 + Formation of Mg 2+

26. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 26  When nonmetals gain electrons to achieve an octet arrangement, they form negative ions.  The ionic charge of a nonmetal is 3-, 2-, or 1-. Formation of Negative Ions

27. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 27 Fluorine forms an octet by adding an electron to its seven valence electrons.     1 - : F  + e  : F :     1s 2 2s 2 2p 5 1s 2 2s 2 2p 6 (= Ne) A negative ion forms with a -1 charge. Fluorine atom Fluoride ion 9 p + 9 p + 9 e - 10 e - 0 1 – Formation of a Fluoride Ion, F -

28. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 28 Group Number and Ions The Group number can be used to determine the charge of an ion. The charge of a positive ion is equal to its Group number. Group 3A = 3+ The charge of a negative ion is obtained by subtracting its Group number from 8. Group 6A = - (8-6) = 2-

29. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 29 Examples of Ionic Charges

30. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 30 A.How many valence electrons does aluminum have? 1) 2e - 2) 3e - 3) 5e - B.How does aluminum acquire an octet? 1) loses 3e - 2) gains 3e - 3) gains 5e - C. What is the ionic charge of an aluminum ion? 1) 3- 2) 5- 3) 3 + D. The symbol for the aluminum ion is 1) Al 3+ 2) Al 3- 3) Al + Learning Check

31. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 31 A.How many valence electrons does aluminum have? 2) 3e - B.How does aluminum acquire an octet? 1) loses 3e - C. What is the ionic charge of an aluminum ion? 3) 3 + D. The symbol for the aluminum ion is 1) Al 3+ Solution

32. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 32 Chapter 4 Compounds and Their Bonds 4.3 Ionic Compounds 4.4 Naming and Writing Ionic Formulas

33. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 33  Ionic compounds consist of positive and negative ions.  An ionic bond is an attraction between the positive and negative charges.  In an ionic formula, the total charge of the positive ions is equal to the total charge of the negative ions. total positive charge = total negative charge Ionic Compounds

34. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 34 The formulas of ionic compounds are determined from the charges on the ions. atoms ions     – Na  +  F :  Na + : F :  NaF     sodium fluorine sodium fluoride The overall charge of NaF is zero (0). (1+ ) + (1-) = 0 Ionic Formulas

35. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 35 Charge Balance In NaCl The formula does not show the charges of the ions in the compound. The symbol of the metal is written first, followed by the symbol of the nonmetal.

36. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 36 Charge Balance In MgCl 2

37. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 37 Writing Formulas Because compounds are electrically neutral, one can determine the formula of a compound this way: The charge on the cation becomes the subscript on the anion. The charge on the anion becomes the subscript on the cation. If these subscripts are not in the lowest whole-number ratio, divide them by the greatest common factor.

38. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 38 Write the formula of the ionic compound that forms from Ba 2+ and Cl . Write the symbols of the positive ion and the negative ion. Ba 2+ Cl  Balance the charges until the positive charge is equal to the negative charge. Ba 2+ Cl  two Cl - needed Cl  Write the formula using subscripts for the number of ions for charge balance. BaCl 2 Writing a Formula from Charges

39. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 39 Write the correct formula for the ionic compound of A. Na + and S 2- 1) NaS 2) Na 2 S3) NaS 2 B. Al 3+ and Cl - 1) AlCl 3 2) AlCl 3) Al 3 Cl C. Mg 2+ and N 3- 1) MgN 2) Mg 2 N 3 3) Mg 3 N 2 Learning Check

40. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 40 A. Na + and S 2- 2) Na 2 S B. Al 3+ and Cl - 1) AlCl 3 C. Mg 2+ and N 3- 3) Mg 3 N 2 Solution

41. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 41 Names of Ions Positive ions are named like the element. Negative ions are named by changing the end of the element name to –ide.

42. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 42 Complete the names of the following ions: N 3  O 2  F  _________ __________ _________ P 3  S 2  Cl  _________ __________ _________ Br  _________ Learning Check

43. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 43 N 3  O 2  F  nitride oxide fluoride P 3  S 2  Cl  phosphide sulfide chloride Br  bromide Solution

44. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 44 The name of a binary ionic compound (two elements) gives the name of the metal ion first and the name of the negative ion second. Examples: NaClsodium chloride K 2 Spotassium sulfide CaI 2 calcium iodide Al 2 O 3 aluminum oxide Naming Ionic Compounds with Two Elements

45. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 45 Write the names of the following compounds: 1) Na 3 N___________ 2) KBr___________ 3) Al 2 S 3 ___________ 4) MgO___________ Learning Check

46. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 46 Complete the names of the following compounds: 1)Na 3 Nsodium nitride 2)KBrpotassium bromide 3)Al 2 S 3 aluminum sulfide 4)MgOmagnesium oxide Solution

47. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 47  Most transition elements have two or more positive ions. Ionic Charges of Transition Metals

48. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 48 Summary of Common Ions Of the transition metals, silver and zinc are important elements that form only one ion.

49. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 49 A. The formula for the ionic compound of Na + and O 2- is 1) NaO2) Na 2 O3) NaO 2 B. The formula of a compound of aluminum and chlorine is 1) Al 3 Cl2) AlCl 2 3) AlCl 3 C. The formula of Fe 3+ and O 2- is 1) Fe 3 O 2 2) FeO 3 3) Fe 2 O 3 Learning Check

50. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 50 A. The formula for the ionic compound of Na + and O 2- is 2) Na 2 O B. The formula of a compound of aluminum and chlorine is 3) AlCl 3 C. The formula of Fe 3+ and O 2- is 3) Fe 2 O 3 Solution

51. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 51 Naming Compounds with Transition Metals Transition metals with two different ions use a Roman numeral following the name of the metal to indicate ionic charge.

52. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 52 Learning Check Select the correct name for each. A. Fe 2 S 3 1) iron sulfide 2) iron(II) sulfide 3) iron (III) sulfide B. CuS 1) copper (II) sulfide 2) copper(I) sulfate 3) copper (II) sulfate

53. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 53 Solution Select the correct name for each. A. Fe 2 S 3 3) iron (III) sulfide B. CuS 1) copper (II) sulfide

54. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 54 Learning Check The correct formula is A. Copper (I) nitride 1) CuN2) CuN 3 3) Cu 3 N B. Lead (IV) oxide 1) PbO 2 2) PbO 3) Pb 2 O 4

55. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 55 Solution The correct formula is A. Copper (I) nitride 3) Cu 3 N B. Lead (IV) oxide 1) PbO 2

56. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 56  Arrhenius acids  Produce H + ions in water. H 2 O HCl H + (aq) + Cl – (aq)  Are electrolytes.  Have a sour taste.  Corrode metals.  React with bases to form salts and water. Acids

57. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 57  Arrhenius bases  Produce OH – ions in water.  Taste bitter or chalky.  Are electrolytes.  Feel soapy and slippery.  React with acids to form salts and water. Bases

58. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 58 Names of Acids Acids with H and one nonmetal are named with the prefix hydro- and end with -ic acid. HClhydrochloric acid Acids with H and a polyatomic ion are named by changing the end of an –ate ion to -ic acid and an –ite ion to -ous acid. HClO 3 chloric acid HClO 2 chlorous acid

59. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 59 Some Acids and Their Anions

60. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 60 Name each of the following as acids: A. HBr 1. bromic acid 2. bromous acid 3. hydrobromic acid B. H 2 CO 3 1. carbonic acid 2. hydrocarbonic acid 3. carbonous acid Learning Check

61. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 61 A. HBr3. hydrobromic acid The name of an acid with H and one nonmetal begins with the prefix hydro- and ends with -ic acid. B. H 2 CO 3 1. carbonic acid An acid with H and a polyatomic ion is named by changing the end of an –ate ion to -ic acid. Solution

62. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 62  Bases with OH - ions are named as the hydroxide of the metal in the formula. NaOHsodium hydroxide KOH potassium hydroxide Ba(OH) 2 barium hydroxide Al(OH) 3 aluminum hydroxide Fe(OH) 3 iron (III) hydroxide Some Common Bases

63. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 63 Match the formulas with the names: A. ___ HNO 2 1) hydrochloric acid B. ___Ca(OH) 2 2) sulfuric acid C. ___H 2 SO 4 3) sodium hydroxide D. ___HCl4) nitrous acid E. ___NaOH5) calcium hydroxide Learning Check

64. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 64 Match the formulas with the names: A. 4 HNO 2 4) nitrous acid B. 5 Ca(OH) 2 5) calcium hydroxide C. 2 H 2 SO 4 2) sulfuric acid D. 1 HCl 1) hydrochloric acid E. 3 NaOH3) sodium hydroxide Solution