1. Ch 6: Bonding, Formulas and Naming Notes

2. Bonding Objectives Chem 5.0: Bonding, Formulas and Naming - OBJECTIVES Describe Ionic Bonding Theory. Describe Covalent Bonding Theory. Write formulas and names for ionic compounds including binary, tertiary and polyvalent. Write formulas and names for molecules (covalent compounds.) Write formulas and names for hydrates. Write formulas and names for binary and tertiary acids. Write Lewis-Dot structures for ionic compounds. Write structural formulas for covalent compounds. Describe electronegativity and how it affects bond type – ionic, polar covalent and nonpolar covalent.

3. Types of Chemical Bonds: A. Ionic Bonding 1) Positively charged ions are attracted to negatively charged ions, making a neutral compound. 2) Properties of Ionic Compounds: a) high melting points. b) dissolve in water to form solutions that are good conductors of electricity (electrolytes). c) have a large electronegativity difference between elements. d) usually form between metals and nonmetals.

4. 3) The Octet Rule: a) Atoms tend to gain or lose electrons in order to acquire a full set of valence electrons (stable octet). b) Atoms will transfer electrons (e - ) to each other in order to have a full set of valence electrons. c) When electrons are transferred, ionic bonds are formed.

5. 4) Types of Compounds: a) Binary form from monatomic ions – have 1 cation and 1 anion. Ex) Mg +2 O -2 Ca +2 Cl -1 MgO CaCl 2

6. Writing Ionic Formulas *This may not be on your notes, but if you don’t know how to do this it will severely affect your grade*

7. When chemical symbols are by them selves… they are called elements But when chemical symbols combine, they are called...... Chemical Formulas

8. Chemical formulas represent different compounds (chemical substances) If chemical symbols are the “letters” of chemistry, then chemical formulas make up the “words” Examples in a jif

9. Chemical Formulas H 2 O Fe 2 Cl HI CH 4 C 6 H 12 O 6 CaCO 3 SF 6

10. Chemical Formulas Subscripts tell us how many atoms of the respective element that are present in that chemical substance H 2 O – The 2 tells us that there are 2 atoms of Hydrogen for every 1 atom of Oxygen present in water. If there is no subscript present, then it means that there is only one atom present in that substance Methane Methane has four Hydrogens around one central Carbon CH 4

11. Criss – Cross Method of Formula Writing Fe 3+ + O 2-  Fe 2 O 3 FeO +3-2 Fe 2 O 3 Criss-Cross will make ya JUMP JUMP!

12. Criss – Cross Method of Formula Writing Na +1 + Br -1  NaBr NaBr +1 Na Br

13. Na +1 O -2 + 1 - 2 Not Balanced 2 + (- 2) = 0 Balanced Na 2 O 2 x (+1) = +2 1 x (-2) = -2

14. Al +3 O -2 Al +3 O -2 +3 -2 Not Balanced + 6 + (- 6) = 0 Balanced Al 2 O 3 2 x (+3) = +6 3 x (-2) = -6

15. 4) Types of Compounds: b) Tertiary form from polyatomic ions which consists of a group of atoms covalently bonded with a single charge that bond ionically with other ions. Ex. “ammonium sulfate”, NH 4 +1 SO 4 -2 (NH 4 ) 2 SO 4

16. Criss – Cross Method of Formula Writing with Polyatomic Ions NH 4 +1 + O -2  (NH 4 ) 2 O NH 4 O +1-2 (NH 4 ) 2 O

17. 5) Polyvalent Metals: Some metals including, but not limited to the transition metals do not follow the octet rule and may form more than 1 kind of cation. These ions are named with roman numerals to distinguish between them. Ex) Fe +2 iron (II) read “iron two” Fe +3 iron (III) read “iron three” FeCl 2 FeCl 3 Copper (I) sulfate Copper (II) phosphate Cu 2 SO 4 Cu 3 (PO 4 ) 2 iron (II) chloride iron (III) chloride

18. Naming Ionic Compounds Binary Compounds

19. Rules for Naming Ionic Compounds For the Cation –Borrow the name of the element Ex. K + is the “Potassium Ion” Ex. Zn 2+ is the “Zinc Ion” –If an ion has more than one oxidation state Cu +1 is “copper one ion” Cu +2 is “copper two ion”

20. Rules for naming the anion Anion- the negatively charged atom –Use the name of the element followed by the suffix “-ide” Cl - is the Chloride ion O -2 is the Oxide ion P -3 is the Phosphide ion

21. Naming Ionic Compounds When naming ionic binary compounds: –Name the cation’s element name followed by the anion’s name NaCl is “Sodium Chloride” K 2 O is “Potassium Oxide” CuCl 2 is “Copper (II) Chloride” Mg 3 N 2 is “Magnesium Nitride” Al 2 S 3 is “Aluminum Sulfide”

22. Naming Ionic Compounds with Polyatomics Name the Cation Name the Polyatomic ion –Ex. Mg 3 (PO 4 ) 2 –“Magnesium Phosphate”

23. Name this compound: FeO If that’s correct, name this: Fe 2 O 3 How can we distinguish between these compounds? What is the charge on the oxygen in each compound? Then what is the charge on the iron in each compound? Fix the name of the first compound: Iron oxide Iron (II) oxide Iron (III) oxide Fe +2 O -2 Fe +3 O -2 X

24. Bonding Objectives Chem 5.0: Bonding, Formulas and Naming - OBJECTIVES Describe Ionic Bonding Theory. Describe Covalent Bonding Theory. Write formulas and names for ionic compounds including binary, tertiary and polyvalent. Write formulas and names for molecules (covalent compounds.) Write formulas and names for hydrates. Write formulas and names for binary and tertiary acids. Write Lewis-Dot structures for ionic compounds. Write structural formulas for covalent compounds. Describe electronegativity and how it affects bond type – ionic, polar covalent and nonpolar covalent.

25. 6) Lewis Dot Diagrams for elements: Element# of val. ElectronsDot Diagram LiLi  N Be F Ne Au 1 5 2 7 8 2 **Note: Only show s and p orbitals in dot diagram.

26. Electron Dot Diagram for Atoms and Ions

27. 7) Lewis-dot diagram for sodium chloride: [Na + ] [ - ]

28. Lewis-dot diagram for NaCl NaNa + - Ionic Bond Formed Na [Na + ] [ - ]

29. Bonding Objectives Chem 5.0: Bonding, Formulas and Naming - OBJECTIVES Describe Ionic Bonding Theory. Describe Covalent Bonding Theory. Write formulas and names for ionic compounds including binary, tertiary and polyvalent. Write formulas and names for molecules (covalent compounds.) Write formulas and names for hydrates. Write formulas and names for binary and tertiary acids. Write Lewis-Dot structures for ionic compounds. Write structural formulas for covalent compounds. Describe electronegativity and how it affects bond type – ionic, polar covalent and nonpolar covalent.

30. B. Covalent Bonding sharing 1) Covalent Bonds are formed by sharing pairs of electrons between 2 atoms. nonmetals low 2) Usually formed between two nonmetals with a low electronegativity difference. 3) Molecules: covalent a) a group of atoms held together by covalent bonds molecules b) molecular substance – contains molecules

31. 4) Naming : a)uses prefixes: 1 mono- 4 tetra- 7 hepta- 10 deca- 2 di- 5 penta-8 octa- 3 tri- 6 hexa-9 nona- b) end in “ ide ” last c) More electronegative element is written last one d) Only use a prefix on the first element if it is more than one. secondelement e) Always use a prefix for the second element. dihydrogen monoxide Ex) water H 2 O dihydrogen monoxide nitrogen dioxide smog NO 2 nitrogen dioxide

32. SF 6 (Sulfur Hexafluoride) Cool little video

33. 5) Types of formulas for covalent bonding many compound a) Molecular Formula shows how many atoms make up a compound. CH 4 H 2 O ex. CH 4 & H 2 O bonded b) Structural Formula shows how the atoms are bonded to each other. ex.

34. dots 1. Uses 2 dots to show an unshared pair of electrons electrons. dashes 2. Uses dashes to represent covalent bonds (a shared pair of electrons) in a structural formula. octet 3. The octet rule should be satisfied for each element in the compound. lowest ratio c) Empirical Formula is the lowest whole number ratio of all the elements in the compound. Ex) C 6 H 6 =CH C 6 H 12 O 6 =CH 2 O

35. 6) Multiple Bonds – can be used to satisfy the octet rule 1 Single Bonds – Share 1 pair of electrons. Ex) methane or phosphorous trichloride

36. 2 Double Bonds – Share 2 pairs of electrons. Ex) formaldehyde

37. 3 strongest Triple Bonds – Share 3 pairs of electrons ( strongest bond). Ex) ethyne

39. Bonding Objectives Chem 5.0: Bonding, Formulas and Naming - OBJECTIVES Describe Ionic Bonding Theory. Describe Covalent Bonding Theory. Write formulas and names for ionic compounds including binary, tertiary and polyvalent. Write formulas and names for molecules (covalent compounds.) Write formulas and names for hydrates. Write formulas and names for binary and tertiary acids. Write Lewis-Dot structures for ionic compounds. Write structural formulas for covalent compounds. Describe electronegativity and how it affects bond type – ionic, polar covalent and nonpolar covalent.

40. 8) Properties of Covalent Bonds meltingbrittleodor conductors a) Low melting points, brittle, strong odor, poor conductors of electricity. large uneven b) Polar Bonds – form between elements with large differences in electronegativity. These have an uneven sharing of electrons. Ex) water

41. Ionic or Covalent? Polar-covalent bonding- a covalent bond in which the bonded atoms have an unequal attraction for the shared electrons In the fight for electrons, Igor wins (most of the time)

42. equalpull c) Nonpolar bonds – exert equal pull on the electrons. Ex) O 2

43. Ionic or Covalent? Nonpolar covalent bonding- A covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge

44. 9) Electronegativity Chart is used to determine bond type non polar covalent polar covalent ionic bonds 0 0.4 1.9 4.0 even sharing uneven sharing electrons transferred

45. C. Ionic & Covalent Bonds Summary: Ionic BondingCovalent Bonding metal-nonmetal e - transferred large electronegativity difference (>1.9) ions formed written cation (+) anion (-) name cation - name anion forms ionic compound (formula unit) in a crystal lattice Written with a chemical or empirical formula NaCl – sodium chloride nonmetal-nonmetal e - shared electronegativity difference (0  1.9) no ions more electronegative element written last use # prefixes/ends in ide forms molecules Written with a molecular or structural formula CCl 4 – carbon tetrachloride

47. carbon tetrachloride

48. Bonding Objectives Chem 5.0: Bonding, Formulas and Naming - OBJECTIVES Describe Ionic Bonding Theory. Describe Covalent Bonding Theory. Write formulas and names for ionic compounds including binary, tertiary and polyvalent. Write formulas and names for molecules (covalent compounds.) Write formulas and names for hydrates. Write formulas and names for binary and tertiary acids. Write Lewis-Dot structures for ionic compounds. Write structural formulas for covalent compounds. Describe electronegativity and how it affects bond type – ionic, polar covalent and nonpolar covalent.

49. D. Acids: H anion 1) A molecular compound that dissolves in water to produce H and a characteristic anion. ionic 2) In water, acids behave like ionic compounds. H COOH 3) Most acid formulas begin with H. (Except organic acids) “ COOH” charge 4) The number of hydrogens in the formula depends upon the charge of the anion.

50. 5) Types of Acids carboxylic a.) Organic Acids contain the carboxylic group, -COOH or CH 3 COOH acetic acid (vinegar) Ex) CH 3 COOH acetic acid (vinegar)

51. hydrogen anion b.) Binary Acids contain hydrogen and 1 type of anion. A two-word name is used for binary acids. 1st word:prefix is “hydro” root is formed from the anion anion suffix “ide” is changed to “ic” 2nd word: is “acid” Ex) HCl anion is chloride hydrochloric acid Prefix root suffix hydrobromic acid HBr anion is bromide hydrobromic acid

52. oxygen c.) Oxo (Tertiary) Acids: contain oxygen within a polyatomic ion. A two-word name is used for oxo acids. H 2 SO 4 H 2 SO 3 sulfur or phosphor (to sound better) 2nd word is “acid” If you “ate” something you don’t like, you say “ic” sulfatesulfuric acid sulfitesulfurous acid

53. HNO 3 anion is nitr ate nitric acid root suffix H 3 PO 3 anion is phosph ite Nitrous acid, anion is formula is: Phosphoric acid, anion is formula is: phosphor ous acid nitr ite HNO 2 phosph ate H 3 PO 4

54. E. Hydrates: 1.) Ionic compounds that absorb H 2 O into their solid structures. magnesium sulfate heptahydrate Ex) magnesium sulfate heptahydrate (epsom salt) Formula: MgSO 4  7H 2 O substance without water MgSO 4 2.) Anhydrous substance – substance without water MgSO 4 Ex) CuSO 4 5H 2 O CuSO 4 – anhydrate (light blue/white) copper (II) sulfate pentahydrate (bright blue)