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. N 3+ –B. S 6+ –C. O 2- –D. Ca + –E. Cl +

15. Problems Which of the following ions occurs commonly? –A. P 3+ –B. Br 7+ –C. O 6+ –D. Ca 2+ –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. O 2 - oxide –B. Al 3+ aluminum –C. NO 3 - nitrate –D. PO 4 3- phosphate –E. CrO 4 2- chromate

21. Problem Which one of the following combinations of names and formulas of ions is incorrect? –A. O 2- oxide –B. Cd 2+ cadmium –C. ClO 3 - chlorate –D. HCO 3 - hydrogen carbonate –E. NO 2 - nitrate

22. Problem Which one of the following combinations of names and formulas of ions is incorrect? –A. Ba 2+ barium –B. S 2- sulfate –C. CN - cyanide –D. ClO 4 - perchlorate –E. HCO 3 - 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, MgF 2, 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, CoCl 2, 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 MnSO 4. 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, KClO 3, 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, (NH 4 ) 2 S, 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. Na 1 O 1 –C. Na 2 O 1 –D. Na 2 O –E. Na 2 O 2

34. Problem Barium fluoride is used in embalming and in glass manufacturing. Which of the following gives the formula for barium fluoride? –A. BaF 2 –B. Ba 1 F 2 –C. BaF –D. BaF 1 –E. Ba 2 F

35. Problem Zinc acetate is used in preserving wood and in manufacturing glazes for porcelain. What is its formula? –A. ZnAc 2 –B. ZnCH 3 COO –C. Zn(CH 3 COO) 2 –D. Zn 2 CH 3 COO –E. ZnCH 3 COCH 3

36. Problem Barium sulfate is used in manufacturing photographic paper. What is its formula? –A. BaSO 4 –B. Ba(SO 4 ) 2 –C. Ba 2 SO 4 –D. Ba 2 (SO 4 ) 3 –E. BaSO 3

37. Problem What is the formula for lead (II) oxide? –A. PbO –B. PbO 2 –C. Pb 2 O –D. PbO 4 –E. Pb 2 O 3

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 acids and 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