2. Chemistry CPA Unit 4 Notes: Compounds and Nomenclature West Essex Regional High School 2013-2014 Callahan, Pengitore & Ricafort

3. NJCCCS & Common Core NJCCCS - 5.2.12.B.1: An atom’s electron configuration, particularly of the outermost electrons, determines how the atom interacts with other atoms. Chemical bonds are the interactions between atoms that hold them together in molecules or between oppositely charged ions. Model how the outermost electrons determine the reactivity of elements and the nature of the chemical bonds they tend to form. Common Core LLA: CCSS.ELA-Literacy.RST.11-12.4: Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 11–12 texts and topics. CCSS.ELA-Literacy.RST.11-12.5: Analyze how the text structures information or ideas into categories or hierarchies, demonstrating understanding of the information or ideas. CCSS.ELA-Literacy.RST.11-12.9: Synthesize information from a range of sources (e.g., texts, experiments, simulations) into a coherent understanding of a process, phenomenon, or concept, resolving conflicting information when possible.

4. Unit Objectives: Chapter 4 Distinguish the properties of compounds from those of the elements of which they are composed. Compare and contrast the properties of sodium chloride, water, and carbon dioxide Model the two types of compound formation, ionic and covalent, at the atomic level Demonstrate how and why atoms achieve chemical stability by bonding Compare, using examples, the effect of covalent and ionic bondings on the physical properties of compounds Chapter 5 Apply ionic charge to writing formulas for ionic compounds. Apply formulas to name ionic compounds Interpret the information in a chemical formula Compare the properties of covalent and ionic substances. Distinguish among allotropes of an element Apply formulas to name covalent compounds.

5. Formation of Compounds Chapter 4

6. Element Properties vs. Compounds Properties: What’s the difference? Sodium and Chlorine Sodium as an element (Na) – Shiny, white, soft, solid metal Melting point - 98°C Extremely reactive with water and air! Chlorine as an element (Cl) Pale green, poisonous gas with choking odor and kills living cells Extremely hazardous to society Sodium Chloride (NaCl) Two dangerous elements combine to form a safe substance we use each day! Tiny white crystals (which are brittle) Melting point of 800°C! Not a conductor Used as table salt, in recipes and as a food preservative Natural part of the human diet

7. Sodium ChlorineSodium Chloride

8. Element Properties vs. Compounds Properties: What’s the difference? Carbon and Oxygen Carbon as an element (C) Nonreactive at room temp Can be in forms of charcoal, diamonds and graphite Oxygen as an element (O) Colorless, odorless, tasteless gas Humans need it to breath Rusting is due to reaction with oxygen Carbon Dioxide (CO 2 ) Colorless, odorless gas at room temperature More dense than air When cooled below -80°C it goes from a gas right to a white solid Can make Carbon Dioxide simply by burning carbon in air Used in photosynthesis Application and Critical thinking - What do power plants use to create energy? How does the burning of that substance produce carbon dioxide? Why do you think an abundance of carbon dioxide is bad for our atmosphere?

9. Carbon Oxygen Carbon Dioxide (CO 2 )

10. Element Properties vs. Compounds Properties: What’s the difference? Hydrogen and Oxygen Hydrogen (H) as an element Colorless, odorless, tasteless gas Reactive and reacts vigorously with other elements Oxygen (O) – we learned about that above. Water (H 2 O) Universal solvent Important everywhere – from rivers from blood Only one of three substances that occurs naturally in the environment in all three states of matter (ice, water, vapor) Important component of nearly all biochemical reactions

11. Hydrogen OxygenWater

12. Chemical Bonds

13. Why and how do you suppose elements are mostly found in compounds and not alone? Think about their valence electrons! And quietly answers in the space provided.

14. Electrons Review Atomic number = number of Electrons Electrons vary in the amount of energy they possess, and they occur at certain energy levels or electron shells Electron shells determine how an atom behaves when it encounters other atoms The first shell wants a maximum of 2 electrons, and all others want a maximum of 8 electrons. Valence shell filling is the ultimate goal of ALL atoms. They bond and react IN ORDER to fill their valence shell.

15. Octet Rule = atoms tend to gain, lose or share electrons so as to have 8 electrons C would like to N would like to O would like to Gain 4 electrons Gain 3 electrons Gain 2 electrons

16. Why are electrons important? Elements have different electron configurations Different electron configurations mean different levels of bonding

18. Take a look at the diagram and answer the following questions: 1.Review: A. X would be the electron dot formula for 1) Na2) K3) Al B. X would be the electron dot formula 1) B2) N3) P 2.Exercise – draw the Lewis dot structures for the first 18 elements on the periodic table. 3.What elements do you see that could “hook up” with one another to create a “partnered” 8-valence electron shell?

19. Electron Dot Structures Symbols of atoms with dots to represent the valence-shell electrons 1 2 13 14 15 16 17 18 H  He:            Li  Be   B   C   N   O  : F  : Ne :                    Na  Mg   Al   Si   P   S  : Cl  : Ar :        

20. Atoms form partnerships by making bonds 1.Atoms share or exchange their electrons with another atom or atoms in order to share a completed valence shell. 2.When they “hook up”, it’s called a bond. 3.There are two types of bonds: 1.Ionic 2.Covalent

21. Properties of Ionic Compounds Hard solids that have a crystal appearance and structure at room temperatures Are referred to as “salts” Ions are held together in very organized and tight/strong bonds which take an enormous amount of energy to break Soluble in water Electrolytes – conduct electricity when dissolved in water

22. Ionic Bonds bond formed between two ions by the transfer of electrons Ionic compounds form when metals bond to nonmetals. Metals loose or give their electrons away to match the number of valence electrons of their nearest noble gas, forming cations Nonmetals gain or take electrons from a metals to match the number of valence electrons of their nearest noble gas forming anions

23. Metals Loose, Nonmetals Gain Sodium LoosingChlorine Gaining

24. More on Metals Loosing… Positive ions form when the number of electrons are less than the number of protons Group 1 metals  ion 1+ Group 2 metals  ion 2+ Group 13 metals  ion 3+

25. Formation of Sodium Ion Sodium atom Sodium ion Na  – e   Na + 1 st shell: 2 1 st shell: 2 2 nd shell: 82 nd shell: 8 3 rd shell: 1 ( = Ne’s configuration!) (2-8-1)(2-8) 11 p + 11 p + 11 e - 10 e - 0 1 +

26. Formation of Magnesium Ion Magnesium atom Magnesium ion  Mg  – 2e   Mg 2+ 1 st shell: 2 2 nd shell: 82 nd shell: 8 3 rd shell: 2 ( = Ne’s configuration!) (2-8-2)(2-8) 12 p + 12 p + 12 e- 10 e - 0 2 +

27. Some Typical Ions with Positive Charges (Cations) Group 1Group 2Group 13 H + Mg 2+ Al 3+ Li + Ca 2+ Na + Sr 2+ K + Ba 2+

28. Learning Check A. Number of valence electrons in aluminum 1) 1 e - 2) 2 e - 3) 3 e - B. Change in electrons for Al’s octet 1) lose 3e - 2) gain 3 e - 3) gain 5 e - C.Ionic charge of aluminum 1) 3- 2) 5- 3) 3 +

29. Solution A. Number of valence electrons in aluminum 3) 3 e - B. Change in electrons for octet 1) lose 3e - C.Ionic charge of aluminum 3) 3 +

30. Learning Check Give the ionic charge for each of the following: 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- 2) 3+ 2) 3-3) 5-

31. More on Nonmetals Gaining… In ionic compounds, nonmetals in 15, 16, and 17 gain electrons from metals Nonmetals add electrons to achieve the octet arrangement Nonmetal ionic charge: 3-, 2-, or 1-

32. Fluoride Ion unpaired electronoctet     1 - : F  + e  : F :     1 st shell: 2 1 st shell: 2 2 nd shell: 72 nd shell: 8 (2-8-1) ( = Ne’s configuration!) (2-8) 9 p+ 9 p + 9 e- 10 e- 0 1 - ionic charge

33. Ions happen because of bonding Ionic Bond: Between atoms of metals and nonmetals with very different electronegativity Bond formed by transfer of electrons Produce charged ions all states. Conductors Have high melting point. Examples; NaCl, CaCl 2, K 2 O

34. Ionic bond – electron from Na is transferred to Cl, this causes a charge imbalance in each atom. The Na becomes (Na+) and the Cl becomes (Cl-), charged particles or ions.

35. Practice – Predict the ion that will form with each element listed below. Show your work!!! 1. Ca 2. P 3. S 4. K 5. Br

36. Properties of Covalent Compounds Composed of molecules held together by strong forces called covalent bonds which aren’t based on charge. Molecules are held together by intermolecular forces which are weaker than the force that hold ions together. Tend to be liquids or gases at room temperature. Not conductors of electricity Don’t usually dissolve in water

37. Covalent Bond bond formed by the sharing of electrons Between nonmetallic elements of similar electronegativity. Formed by sharing electron pairs Stable non-ionizing particles, they are not conductors at any state Examples; O 2, CO 2, C 2 H 6, H 2 O, SiC

39. There are Two Types of Covalent Bonds… Nonpolar Covalent Polar Covalent

40. when electrons are shared equally NONPOLAR COVALENT BONDS H 2 or Cl 2

41. Oxygen Atom Oxygen Molecule (O 2 ) Oxygen Molecule (O 2 ) O 2 is an example of a nonpolar covalent bond

42. when electrons are shared unequally POLAR COVALENT BONDS H2OH2O

43. - water is a polar molecule because oxygen is more electronegative than hydrogen, and therefore electrons are pulled closer to oxygen.

44. Practice: Tell whether the examples below are elements, ionic compounds or covalent compounds. 1.Potassium (K) 2.Lithium fluoride (LiF) 3.Carbon dioxide (CO 2 ) 4.Oxygen gas (O 2 ) 5.Cobalt (Co)

45. Writing Formulas and Naming Compounds Chapter 5

46. Naming a Binary Ionic Compound A binary compound is one in which contains only two elements. To name a binary compound, identify the cation and anion. name the cation first name of the anion second, but change the ending to “-ide” Examples: Sodium + Chlorine = Sodium Chloride Magnesium + Oxygen = Magnesium Oxide

48. 47 Complete the names of the following ions. Ba 2+ Al 3+ K + _________ __________ _________ N 3  O 2  F  _________ __________ _________ P 3  S 2  Cl  _________ __________ _________ Learning Check

49. Practice – Naming Binary Ionic Compounds 1.Lithium + Nitrogen 2.KCl 3.Strontium + Selenium 4.MgCl 2 5.Calcium + Chlorine 6.Al 2 O 3

50. Writing Formulas for Binary Ionic Compounds 1.Write the symbol for the metal first with the charge Example: Magnesium, Mg 2+ 2.Write the symbol for the nonmetal next with the charge Example: Chlorine, Cl 1- 3.Crisscross the number of the charge (don’t write a number if the charge is -1 or +1) Example: Mg 2+ Cl 1- MgCl 2 4.All compounds are neutral, so the charges must add to ZERO: 1(+2) + 2(-1) = 2 – 2 = 0

51. 50 Charges of Representative Elements Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

52. Names of Some Common Ions

53. Learning Check Write the formulas and names for compounds of the following ions: Br − S 2− N 3− Na + Al 3+

54. EXAMPLES Different Charges: 1. Aluminum sulfide Al +3 S -2 Al 2 S 3 2. Calcium chloride Ca +2 Cl -1 CaCl 2 Equal but opposite charges: 3. Magnesium oxide Mg +2 and O -2 Mg 2 O 2 this can be reduced to MgO

55. Practice – forming binary ionic compounds Calcium and Oxygen Aluminum and Fluorine Boron and Oxygen Strontium and Nitrogen Barium and Selenium Ions with charges Ca 2+ O 2- Criss-cross and drop Charge Formula: Ca 2 O 2 Reduces to 0: CaO Name:

56. Naming when the metal forms more than one charge Look at the Periodic Table – some elements have more than one charge – Transition Metals Ex: Copper +1 or +2 Roman Numerals are used to indicate the charge. Copper (I) or Copper (II) Cu +1 or Cu +2 Example: Copper (Cu +2 ) and Chlorine (Cl 1- ) Writing the name: Copper (II) chloride Writing the formula: CuCl 2

57. Common Roman Numerals NumberRoman Numeral 1I 2II 3III 4IV 5V 6VI 7VII 8VIII 9IX 10X

58. Naming compounds that have metals with multiple charges – THE TRICK… Determine the charge by working backwards Write the charge in roman numerals in the name CuF 2 Copper is either +1 or +2 charge In this case it is +2 since there are two Fluorine atoms for every one copper (F is always -1 charge) Copper (II) Fluoride

59. Practice – write the formula and name Chromium (2+) and Chlorine Lead (2+) and Oxygen Manganese (3+) and iodine Iron (3+) and Oxygen Write the ions with their charges Criss-Cross and drop the charge – Formula Name

60. Practice – Predict the charge & formula from the formula Iron (III) ChlorideLead (IV) FluorideNickel (III) BromideMercury (II) oxide Write the IonsCl 1- Criss- cross and drop charge Formula

61. Polyatomic Ions What are they? An ion that has two or more different elements The ion is a group of atoms held together by covalent bonds. The group as a whole has a charge, so it acts just like an anion, which the exception of the Ammonium (NH 4 ) + ion

62. How To Handle Polyatomic Ions… Always include parenthesis around these ions End in –ate or –ite Exceptions – Hydroxide, Cyanide, Ammonium Found on the back of your periodic table!

63. Common Polyatomic Ions

64. Naming Compounds with Polyatomic Ions Metal bonded to a polyatomic ion Al 2 (SO 4 ) 3 1.Name the metal 2.Name the polyatomic ion as it appears on the back of your periodic table

65. Examples MgSO 4 CaCO 3 Sn(OH) 4

66. Writing Formulas for Compounds with Polyatomic Ions 1.Write the symbol for the metal and charge 2.Write the polyatomic ion in parenthesis and with charge outside 3.Criss-cross the charges

67. Practice making formulas for compounds with polyatomic ions Magnesium HydroxideSodium SulfateCalcium CarbonateAluminum Sulfite Write the Ions with their charges – put polyatomics in parenthesis with charge outside!! Mg 2+ (OH) - Criss-cross and drop charge outside parenthesis Formula Mg(OH) 2

68. Naming Molecular (Covalent) Compounds Two non-metals bonded together; shared bond of electrons Example: CO 2 = carbon dioxide Prefixes are used to express the number of each element The second nonmetal ends in –ide Never reduce!!

69. Prefixes NumberPrefix 1mono- 2di- 3tri- 4tetra- 5penta- 6hexa- 7hepta- 8octa- 9nona- 10deca- ATTENTION!!! The prefix mono- is not used with the first named element Use the back of your periodic table to help you

70. Practice Naming Covalent/Molecular Compounds Compoun d SO 3 N2O5N2O5 COC 2 Br 6 Name

71. Practice Writing Formulas for Covalent/Molecular Compounds Namepentacarbon decahydridetetrasulfur heptoxidecarbon monobromideIodine trichloride Compound

72. Naming and Writing Formulas for Hydrocarbons Compounds containing Carbon are organic compounds Hydrocarbon is an organic compound that contains only Carbon (C) and Hydrogen (H) Hydrocarbons occur naturally as fossil fuels such as coal, natural gas, and petroleum All carbon atoms can form 4 covalent bonds.

73. Table 5.8 (p.180) Hydrocarbons FormulaName CH 4 methane C2H6C2H6 ethane C3H8C3H8 propane C 4 H 10 butane C 5 H 12 pentane C 6 H 14 hexane C 7 H 16 heptane C 8 H 18 octane C 9 H 20 nonane C 10 H 22 decane