1. Chapter 4 Ionic Compounds

2. Chemical Bonds • 2-types of bonding are found in compounds • Ionic bond – Chapter 4 • Covalent bond – Chapter 5

3. Ions • Ionic compounds – substances comprised of ions of a metal combined with ions of a nonmetal or group of non-metals

4. Ions • Metals • Lose electrons • Forms a cation • Nonmetals • Gain electrons • Forms an anion

5. Ions and the Octet Rule • Stated • Metals form cations • Nonmetals form anions • Why? • An ion is formed so that the atom achieves noble gas configuration • Octet Rule – main group elements tend to undergo reactions that leave them with 8 electrons in outer shell • Outer shell – valence shell – highest period # • Outer electrons – valence electrons – e- in highest period #

7. Electron-Dot Symbols • Electron-dot symbol – An atomic symbol with dots placed around it to indicate the number of valence electrons

8. Periodic Properties and Ion Formation • Ease by which an element forms a cation or anion is determined by the energy involved

9. Periodic Properties and Ion Formation • Ease by which a cation is formed – ionization energy • Metals have lower ionization energies than nonmetals • Ionization energy increases across a period • Ionization energy decreases down a group

10. Periodic Properties and Ion Formation • Ease by which an anion is formed – electron affinity • Nonmetals have larger electron affinities • Electron affinity values become more negative across a group • Electron affinity values become less negative down a group

11. Ionic Bond • Ionic bond – the glue that holds the metal and nonmetal together • Electrostatic attraction (magnets) – occurs when opposites attract

12. Some Properties of Ionic Compounds • Usually crystalline • Ions in a solid do not move – do not conduct electricity • Once dissolved – ions move freely and conduct electricity • High melting and boiling points • Ionic solids shatter if struck hard • Ionic compounds dissolve in water if the attraction of ions to water is greater than the ions attraction to each other

13. Ionic Bonds

14. Problem • Which of the following ions occurs commonly?  • A.  N3+ • B.  S6+ • C.  O2- • D.  Ca+ • E.  Cl+

15. Problems • Which of the following ions occurs commonly?  • A.  P3+ • B.  Br7+ • C.  O6+ • D.  Ca2+ • E.  K-

16. Ionic Bonds

17. Naming Ions • Group 1A, Group 2A, Al, Ga, In, Zn, Sc, Ag, Cd, Ru ions • Give name of element followed by word ion • All other metals • Give name of element + charge in parenthesis (roman numerals) followed by word ion • Element anions • Replace the ending of the element name with -ide

18. Polyatomic Ions • Polyatomic ion • Poly – many • Atomic – atom • Ion – ion • Think of them as a chemical unit • States which atoms are present, exact # atoms present and the charge

19. Polyatomic Ions

20. Problem • Which one of the following combinations of names and formulas of ions is incorrect?  • A.  O2- oxide • B.  Al3+ aluminum • C.  NO3- nitrate • D.  PO43- phosphate • E.  CrO42- chromate

21. Problem • Which one of the following combinations of names and formulas of ions is incorrect?  • A.  O2- oxide • B.  Cd2+ cadmium • C.  ClO3- chlorate • D.  HCO3- hydrogen carbonate • E.  NO2- nitrate

22. Problem • Which one of the following combinations of names and formulas of ions is incorrect?  • A.  Ba2+ barium • B.  S2- sulfate • C.  CN- cyanide • D.  ClO4- perchlorate • E.  HCO3- bicarbonate

23. Naming Ionic Compounds • Simply combine the names previously discussed in naming ions without the word ion • Determine which element is the cation • Can the cation only have one possible charge • Yes • Give the name of the metal as seen on periodic table • Give the anion the root name of the element followed by the ending –ide • Polyatomic ions – get their name

24. Naming Ionic Compounds • No • Give the name of the metal as seen on periodic table • Indicate the charge on the metal • Use roman numerals in parenthesis • Give the anion the root name of the element followed by the ending –ide • Polyatomic ions – get their name

25. Problem • The colorless substance, MgF2, is used in the ceramics and glass industry. What is its name?  • A.  magnesium difluoride • B.  magnesium fluoride • C.  magnesium(II) fluoride • D.  monomagnesium difluoride • E.  none of these choices is correct, since they are all misspelled

26. Problem • The compound, BaO, absorbs water and carbon dioxide readily and is used to dry gases and organic solvents. What is its name?  • A.  barium oxide • B.  barium(II) oxide • C.  barium monoxide • D.  baric oxide • E.  barium peroxide

27. Problem • The substance, CoCl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name?  • A.  cobalt dichloride • B.  cobalt(II) chloride • C.  cobalt chloride • D.  cobaltic chloride • E.  copper(II) chloride

28. Problem • A red glaze on porcelain can be produced by using MnSO4. What is its name?  • A.  manganese disulfate • B.  manganese(II) sulfate • C.  manganese(IV) sulfate • D.  manganese sulfate • E.  manganese(I) sulfate

29. Problem • The substance, KClO3, is a strong oxidizer used in explosives, fireworks, and matches. What is its name?  • A.  potassium chlorite • B.  potassium chloride • C.  potassium(I) chlorite • D.  potassium(I) chlorate • E.  potassium chlorate

30. Problem • The compound, (NH4)2S, can be used in analysis for trace amounts of metals present in a sample. What is its name?  • A.  ammonium sulfide • B.  diammonium sulfide • C.  ammonium sulfite • D.  ammonia(I) sulfite • E.  ammonium(I) sulfide

31. Problem • The substance, CaSe, is used in materials which are electron emitters. What is its name?  • A.  calcium monoselenide • B.  calcium(II) selenide • C.  calcium selenide • D.  calcium(I) selenide • E.  calcium(II) selenium

32. Formulas of Ionic Compounds • Chemical compounds must posses NO charge • Formulas • Determine ions involved • Determine charge on each ion • Cross and drop the magnitude • If the magnitude dropped beside a polyatomic is greater than 1, place the polyatomic ion in parenthesis and magnitude dropped as subscript outside parenthesis • Simplify if the subscripts are divisible by same #

33. Problem • Sodium oxide combines violently with water. Which of the following gives the formula for sodium oxide?  • A.  NaO • B.  Na1O1 • C.  Na2O1 • D.  Na2O • E.  Na2O2

34. Problem • Barium fluoride is used in embalming and in glass manufacturing. Which of the following gives the formula for barium fluoride?  • A.  BaF2 • B.  Ba1F2 • C.  BaF • D.  BaF1 • E.  Ba2F

35. Problem • Zinc acetate is used in preserving wood and in manufacturing glazes for porcelain. What is its formula?  • A.  ZnAc2 • B.  ZnCH3COO • C.  Zn(CH3COO)2 • D.  Zn2CH3COO • E.  ZnCH3COCH3

36. Problem • Barium sulfate is used in manufacturing photographic paper. What is its formula?  • A.  BaSO4 • B.  Ba(SO4)2 • C.  Ba2SO4 • D.  Ba2(SO4)3 • E.  BaSO3

37. Problem • What is the formula for lead (II) oxide?  • A.  PbO • B.  PbO2 • C.  Pb2O • D.  PbO4 • E.  Pb2O3

38. H+ and OH- Ions: An Introduction to Acids and Bases • The importance of the H+ cation and the OH- anion is that they are fundamental to the concepts of acidsand bases. • Acid: A substance that provides H+ ions in water; for example, HCl  H+ + Cl- • Base: A substance that provides OH- ions in water; for example, NaOH  Na+ + OH-

40. Optional Homework • Text – 4.31, 4.32, 4.33, 4.38, 4.46, 4.48, 4.50, 4.52, 4.54, 4.56, 4.60, 4.62, 4.64, 4.66, 4.68, 4.70, 4.72, 4.74, 4.76, 4.90, 4.92, 4.96, 4.98 • Chapter 2 Homework – from website

41. Required Homework • Assignment 4