VSEPR, Hybridization, Polyatomic ions, & Nomenclature Created/Modified by: Laura Peck

1. VSEPR, Hybridization,Polyatomic ions, & NomenclatureCreated/Modified by: Laura Peck

2. To make a chemical bond, atoms Will overlap their outer orbitals

3. The degree of overlap is determined by the system’s potentialenergy equilibrium bond distance The point at which the potentialenergy is a minimum is called the equilibrium bond distance

4. Formation of sp hybrid orbitals The combination of an s orbital and a p orbital produces 2 new orbitals called sp orbitals. 2s These new orbitals are called hybrid orbitals The process is called hybridization What this means is that both the s and one p orbital are involved in bonding to the connecting atoms

5. Formation of sp2hybrid orbitals

6. Formation of sp3hybrid orbitals

7. Hybrid orbitals can be used to explain bonding and molecular geometry

8. VSEPRTheory • Based on Lewis structures we can know the shape or “geometry” of molecules • VSEPR stands for Valence Shell Electron Pair Repulsion • VSEPR, as the name suggests, predicts geometry based on the repulsion of electron pairs (in bonds or by themselves) • Electrons around the central nucleus repel each other. Thus, resulting structures have atoms maximally spread out.

9. VSEPR overview • Each shape containing 2-6 peripheral atoms has a name • Sometimes the molecules are represented by ABY, where Y is the # of peripheral atoms • AB2 = linear • AB3 = planar triangular • AB4 = tetrahedral (tetra = 4 faces) • AB5 = trigonal bipyramidal (2 pyramids) • AB6 = octahedral (octa = 8 faces) • Online chart

10. Rules for Predicting Molecular Geometry 1.  Sketch the Lewis structure of the molecule or ion 2.  Count the electron pairs and arrange them in the way that  minimizes electron-pair repulsion. 3.  Determine the position of the atoms from the way the electron pairs are shared. 4.  Determine the name of the molecular structure from the position of the atoms. 5.  Double or triple bonds are counted as one bonding pair when predicting geometry.

18. Polyatomic ions that you have to memorize (pg 226 of Modern Chem) Ammonium – NH4+ Nitrite – NO2- Nitrate – NO3- Hydroxide – OH- Hypochlorite – ClO- Chlorite – ClO2- Chlorate – ClO3-Perchlorate – ClO4- Carbonate – CO32- Sulfite – SO32- Sulfate – SO42- Peroxide – O22- Phosphate – PO43- For more lessons, visit www.chalkbored.com

19. Let’s practice VSEPR with the polyatomic ions: It’s AB4 = tetrahedral • NH4+ = Trigonal Pyrimidal NO3- It’s AB3E = Angular/bent NO2- It’s AB2E2

20. Nomenclature – Naming of chemical compounds

21. Nomenclature – Naming of chemical compounds Binary Ionic Compounds: • 1. Cation first, then anion • 2. Monatomic cation = name of the element • Ca2+ = calciumion • 3. Monatomic anion = root + -ide • Cl- = chloride • CaCl2 = calcium chloride

22. Naming Binary Ionic Compounds • Examples: NaCl ZnI2 Al2O3 sodium chloride zinc iodide aluminum oxide

23. Learning Check Complete the names of the following binary compounds: Na3N sodium ________________ KBr potassium ________________ Al2O3 aluminum ________________ MgS _________________________

24. Transition Metals (Stock System) Elements that can have more than one possible charge MUST have a Roman Numeral to indicate the charge on the individual ion. 1+ or 2+ 2+ or 3+ Cu+,Cu2+ Fe2+, Fe3+ copper(I) ion iron(II) ion copper (II) ion iron(III) ion

25. Names of Variable Ions These elements REQUIRE Roman Numerals because they can have more than one possible charge: anything except Group 1A, 2A, Ag, Zn, Cd, and Al (You should already know the charges on these!) Or another way to say it is: Transition metals and themetalsin groups 4A and 5A (except Ag, Zn, Cd, and Al) require a Roman Numeral. FeCl3(Fe3+) iron (III) chloride CuCl (Cu+ ) copper (I) chloride SnF4 (Sn4+) tin (IV) fluoride PbCl2 (Pb2+) lead (II) chloride Fe2S3 (Fe3+) iron (III) sulfide

26. Examples of Older Names of Cations formed from Transition Metals(you do not have to memorize these)

27. Learning Check Complete the names of the following binary compounds with variable metal ions: FeBr2 iron (_____) bromide CuCl copper (_____) chloride SnO2 ___(_____ ) ______________ Fe2O3 ________________________ Hg2S ________________________

28. Ternary Ionic Nomenclature Writing Formulas • Write each ion, cation first. Don’t show charges in the final formula. • Overall charge must equal zero. • If charges cancel, just write symbols. • If not, use subscripts to balance charges. • Use parentheses to show more than one of a particular polyatomic ion. • Use Roman numerals indicate the ion’s charge when needed (stock system)

29. Ternary Ionic Nomenclature Sodium Sulfate Na+ and SO4-2 Na2SO4 Iron (III) hydroxide Fe+3 and OH- Fe(OH)3 Ammonium carbonate NH4+ and CO3–2 (NH4)2CO3

30. Naming Ternary Compounds • Contains at least 3 elements • There MUST be at least one polyatomic ion (it helps to circle the ions) *Most polyatomic ions are negatively charged and most are oxyanions – containing oxygen* • Examples: NaNO3 Sodium nitrate K2SO4Potassium sulfate Al(HCO3)3Aluminumbicarbonate or Aluminumhydrogen carbonate

31. Learning Check Match each set with the correct name: 1.Na2CO3a) magnesium sulfite MgSO3b) magnesium sulfate MgSO4c) sodium carbonate 2 . Ca(HCO3)2a) calcium carbonate CaCO3b) calcium phosphate Ca3(PO4)2 c) calcium bicarbonate

32. Mixed Practice! Name the following: • Na2O • CaCO3 • PbS2 • Sn3N2 • Cu3PO4 • HgF2

33. Mixed Up… The Other Way Write the formula: • Copper (II) chlorate • Calcium nitride • Aluminum carbonate • Potassium bromide • Barium fluoride • Cesium hydroxide

34. Naming Molecular Compounds All are formed from two or more nonmetals. CO2 Carbon dioxide Ionic compounds generally involve a metal and nonmetal (NaCl) BCl3boron trichloride CH4 methane

35. Molecular (Covalent) Nomenclaturefor two nonmetals • Prefix System (binary compounds) 1. Less electronegative atom comes first. 2. Add prefixes to indicate # of atoms. Omit mono- prefix on the FIRST element. Mono- is OPTIONAL on the SECOND element (in this class, it’s NOT optional!). 3. Change the ending of the second element to -ide.

36. PREFIX mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca- NUMBER 1 2 3 4 5 6 7 8 9 10 Molecular Nomenclature Prefixes

37. Molecular Nomenclature: Examples • CCl4 • N2O • SF6 • carbon tetrachloride • dinitrogen monoxide • sulfur hexafluoride

38. More Molecular Examples • arsenic trichloride • dinitrogen pentoxide • tetraphosphorus decoxide • AsCl3 • N2O5 • P4O10

39. Learning Check Fill in the blanks to complete the following names of covalent compounds. CO carbon ______oxide CO2 carbon _______________ PCl3 phosphorus _______chloride CCl4 carbon ________chloride N2O _____nitrogen _____oxide

40. Overall strategy for naming chemical compounds.

41. A flow chart for naming binary compounds.

42. Mixed Practice • Dinitrogen monoxide • Potassium sulfide • Copper (II) nitrate • Dichlorine heptoxide • Chromium (III) sulfate • Iron (III) sulfite • Calcium oxide • Barium carbonate • Iodine monochloride

43. Mixed Practice • BaI2 • P4S3 • Ca(OH)2 • FeCO3 • Na2Cr2O7 • I2O5 • Cu(ClO4)2 • CS2 • B2Cl4

44. Acid Nomenclature • Acids • Compounds that form H+ in water. • Formulas usually begin with ‘H’. • In order to be an acid instead of a gas, binary acids must be aqueous (dissolved in water) • Ternary acids are ALL aqueous • Examples: • HCl (aq) – hydrochloric acid • HNO3 – nitric acid • H2SO4 – sulfuric acid

45. Acid Nomenclature Review No Oxygen with Oxygen An easy way to remember which goes with which… “In the cafeteria, you ATE something ICky”

46. Acid Nomenclature Flowchart

47. Acid Nomenclature • HBr (aq) • H2CO3 • H2SO3 hydrobromic acid • No oxygen, -ide • Has oxygen, -ate  carbonic acid  sulfurous acid • Has oxygen, -ite

48. Acid Nomenclature • hydrofluoric acid • sulfuric acid • nitrous acid • 2 elements  H+ F-  HF (aq) • 3 elements, -ic  H+ SO42-  H2SO4  H+ NO2-  HNO2 • 3 elements, -ous

49. Name ‘Em! • HI (aq) • HCl • H2SO3 • HNO3 • HIO4

50. Nomenclature Summary Flowchart