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Summary of Definitions

Summary of Models. Summary of Definitions. Know the Bohr-Rutherford Model / Simplified Model Know Electron: negatively charged particle, very light Proton: positively charged particle ~1 AMU Neutron: neutral particle ~1 AMU. Atomic number (Z) = # protons

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Summary of Definitions

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  1. Summary of Models Summary of Definitions • Know the Bohr-Rutherford Model / Simplified Model • Know • Electron: negatively charged particle, very light • Proton: positively charged particle ~1 AMU • Neutron: neutral particle ~1 AMU • Atomic number (Z) = # protons • Mass number (A) = # protons + # neutrons • Atomic mass (u) : the weighted average of the mass number of all natural isotopes of the element. • Mass numbers (A) are whole • Atomic masses (u) are decimal numbers • In a neutral atoms: # electrons = # protons • In an ion (charged atom) • The ionic charge* = # protons - # electrons * The ionic charge is sometimes called the “oxidation number”

  2. Module 1, Lesson #8 • Chemistry notations • Periodic Table

  3. Symbols and Meaning With sign, ionic charge or oxidation number Average atomic mass (u) if written with a decimal Valence number (without sign) most likely # bonds Isotope mass number (A) (if no decimal) 78.9 79 2 Se – subtract 34 2 Atomic number (Z) Number of protons Number of atoms per molecule Symbol 45 Number of neutrons (A-Z) Uncharged # electrons = Z Actual # electrons = ( Z – oxidation #)

  4. Symbols and Meaning(Summary for Notes) With sign, ionic charge or oxidation number Mass number (A) Valence number (no integer sign) # of bonds 79 2 Se – If it is a decimal number it is called atomic mass (u) 34 2 Atomic number (Z) Equals # of protons Number of atoms per molecule Symbol 45 Number of neutrons (Subtract: A-Z) Uncharged # electrons = Z Actual # electrons = ( Z – oxidation #) Symbols and Meaning

  5. Quick exercise: What does each notation below mean? • Magnesium-25 ion, 12p, 13n, 10e • Sulfur molecule containing 8 atoms of sulfur (each atom has 16p, 16e) • Bromine-80 ion, 35p, 45n, 36e • Typical uncharged Chlorine atom, 17p, 17e and on the average, 18.5 neutrons • A molecule containing 6 atoms of carbon, 12 atoms hydrogen, 6 atoms oxygen 2+ 25 Mg S8 80 Br 1- 35.5 ? Cl 17 C6H12O6

  6. Representative (A Families)and Transitional (B Families) Active Metals

  7. Families in the Periodic Table(Traditional numbering in Roman numerals) I II III IV V VI VII VIII III B IV B V B VI B VII B VIII B I B II B IronTriad* Family 7: Halogens Family 3: Boronfamily Family 4: Carbon Family Family 1: Alkali metal Family 2: Alkaline Earths Family 5: Nitrogen family Family 6: Oxygen family Family 8: Noble gases Palladium Coin metals Chromium Manganese Zinc Family Scandium Titanium Vanadium Platinum Triads Lanthanides (period 6 rare earths) Actinides (period 7 rare earths) *Iron Triad AKA magnetic metals The lower families are sometimes called “B” families. Families, or groups run vertically in the table.

  8. Rows or Periods (number of shells / energy levels) 1st Period = One Shell 2nd Period = Two Shells 3rd Period = Three Shells 4th Period = Four Shells 5th Period = Five Shells 6th Period = Six Shells 7th Period = Seven Shells Six Shells Seven Shells

  9. Regions of the Periodic Table(metals vs. non-metals) NON-METALS METALLOIDS METALS Active Metals METALS , NON-METALS and METALLOIDS

  10. Modern Regions of the Periodic Table(divided into more groups) Other Non­metals Alkali Metals Alkaline Earth (metals) Transition Elements (metals) Other Metals Halogens Rare Earth Elements (metals) Noble (Inert) gas Metalloids

  11. Activity in the Periodic Table F Most Active Active non-metals Active Metals Fr Most Active Metal Inactive *Most Active Metal and Non-metal

  12. Atomic Size in Periodic Table Smallest Atom Bigger AtomsSmaller Atoms Bigger AtomsSmaller Atoms Big Atoms Biggest Atom

  13. Valence Electrons(Electrons in the outer shell) 1e- 2e- 3e- 4e- 5e- 6e- 7e- Full* (2) Mostly 2 electrons in outer shell (but it can vary from 1 to 5) One Two Five Six Four Seven Three Full s & p-orbitals (8) Active Metals *Filled orbitals: full s-orbital for He, full s and p-orbitalsfor all others, (but not necessarily filled d or f orbitals )

  14. Most Probable Valences (Actual valences can vary. Valence with sign is called oxidation number) 1+ 2+ 3+ 4± 3- 2- 1- 0 (2) Many transition element have a valence of 2+, but it can vary from 1+ to 5+. Some transition elements are polyvalent One Two Three Two Four One ZERO Three Active Metals *Filled orbitals:full s-orbital for He, full p-orbitals for all others

  15. Relationship betweenperiodic table and orbitals s p-orbitals d-orbitals s-orbitals Active Metals f-orbitals *For these elements, the outermost electrons are in an s orbital *For these elements, the outermost electrons are in a d orbital *For these elements, the outermost electrons are in a p orbital *For these elements, the outermost electrons are in an f orbital

  16. Summary • Know several different ways of viewing the periodic table, for example: • By representative vs. transitional regions • By metals vs. non-metals (vs. metalloids) • By major Families and regions • Know the relationship between the periodic table and: • Valence electrons • Valence numbers (oxidation numbers) • Number of shells

  17. Module 1, Lesson 9 • Naming compounds • Common names vs. systematic names • Binary compounds • Covalent vs. Ionic Compounds

  18. Compound Names • Every compound must have a unique name. • Many compounds have common names, but some don’t, and some common names are misleading. • A systematic name is devised for each compound by following sets of rules for systematic names. (AKA scientific names)

  19. Examples of Common and Systematic names Don’t copy, Read! • Common name formula systematic name • Water H2O dihydrogen monoxide • Lime CaO calcium oxide • Slaked lime Ca(OH)2 calcium hydroxide • Lye NaOH sodium hydroxide • Potash K2CO3 potassium carbonate • Table salt NaCl sodium chloride • Laughing gas N2O dinitrogen monoxide • Oxygen gas O2 dioxygen • Ozone gas O3 trioxygen • Ammonia NH3 nitrogen trihydride • Methane CH4 carbon tetrahydride • Some compounds only have systematic names: • Carbon dioxide CO2 carbon dioxide • Carbon tetrachloride CCl4 carbon tetrachloride • Organic compounds use a completely different naming system: • Table sugar C12H22O11 sucrose (glucose-fructose disaccharide)

  20. Some common, systematic and other acceptable names

  21. Binary Compounds vs. Ternary Compounds • Binary Compounds • Contain only two elements • Systematic names always end in –ide. • Systematic names are usually quite simple, containing the names of the two elements which make the compound • Example: sodium chloride (NaCl) • Ternary Compounds • Contain more than two elements • Contain “radicals”

  22. Rule Sets • There are Three main sets of rules for naming compounds (with some additional variations) The Covalent Rules are for naming covalent compounds, not including organic covalent compounds The Ionic Rules are for naming ionic compounds with a variation for ternary ionic compounds The Organic Rules are for naming organic compounds, but these are not studied this year

  23. Ionic vs Covalent • Ionic compounds contain ions(charged particles) • A metal atom with a non-metal (in salts) eg: NaCl • A hydrogen ion with a non-metal (in acids) eg: HCl • An ammonium salt starts with NH4… eg: NH4Cl • Covalent compounds contain molecules (uncharged) • They are also called molecular compounds. • Include most compounds with only non-metals. • Excluding acids and ammonium salts, which are ionic • Organic compounds are also contain molecules, but they have lots of carbon (usually more than one carbon atom) • Sugars, alcohols, hydrocarbons,aldehydes, ketones, proteins, nucleic acids, etc.

  24. The Covalent Rules • Covalent (or molecular) compound names often include prefixes. • Mono, di, tri, tetra, penta, hexa, hepta, octo… • The name is always based on the formula • Eg: • N2O4 dinitrogen tetroxide • SF6 sulfur hexafluoride • H2S dihydrogen monosulphide • The “mono” prefix is normally left off of the first element (thus we say sulphur hexafluoride rather than monosulphur hexafluoride). Sometimes it is even left off the second element (but don’t do that unless you are sure!)

  25. Covalent Formulas are NOT Simplified • Formulas like N2H4 (systematic name: dinitrogen tetrahydride, common name: hydrazine) are not simplified by cancellation (ie. Don’t write NH2), • Why? Because the bonding pattern is important in many covalent molecules

  26. A Bad Habit that is Spreading • Some textbooks, including “Quantum Chemistry”, have a habit of dropping the prefixes from the names of the most common covalent compounds: • Eg. The book calls SF2 “sulphur fluoride” instead of “sulphur difluoride” and H2S is called “hydrogen sulphide” instead of “dihydrogen sulphide”. • IUPAC allows the use of some alternate names, but I disagree with this practice. • Why? Because there is another fluoride of sulphur—SF6, “sulphur hexafluoride” so we should specify carefully! • If you encounter a covalent compound that is named this way, use the cross-over rule to determine the most likely formula (although this is not the only possible formula)

  27. Another Bad Habit of Mine • I usually use the spelling “Sulfur” (an Americanization) rather than the accepted Canadian spelling “Sulphur” • It’s the result of reading way too many American textbooks and seeing far too many periodic tables printed in the U.S.A. • I will try to remember the correct spelling, but cut me a bit of slack here! Hey, I will forgive you if you misspell sulf..., I mean, sulphur too.

  28. Quick Exercisedo on a sheet of lined paper. • What is the systematic name of: • N2H4 d. H2O g. SF6 • CF4 e. CO h. SBr2 • N305 f. PO3 i. CS2 What is the formula of: a. Dinitrogen pentoxide b. Sulphur dioxide c. Oxygen difluoride d. diphosphorus tetrachloride a dinitrogen tetrahydride dihydrogen monoxide sulphur hexafluoride b carbon tetrafluoride carbon monoxide sulphur dibromide c trinitrogen pentoxide phosphorus trioxide carbon disulfide N2O5 SO2 OF2 P2Cl4

  29. The Ionic Rules (part 1)Naming Binary Ionic Compound • Ionic compound names do NOT contain prefixes. They simply start with the metallic elements name, followed by the non-metallic portion. • Eg: • Na2O sodium oxide • BaF2 barium fluoride • NaCl sodium chloride • AlCl3 aluminum chloride

  30. The Formulas of Ionic Compounds • The name of an ionic compound does NOT tell you its formula. • But, you can always work out the formula from the name by using the “crossover rule.” • Eg. • What is the formula of potassium oxide? • Potassium has a valence of 1 (ie. 1+) • Oxygen has a valence of 2 (ie 2-) • Write the valences above and to the right: • K1 and O2 • Cross them over and simplify. That gives the formula • K2O1  simplify K2O

  31. Ionic Formulas ARE Simplified • Formulas like Mg4C2 (systematic name: magnesium carbide) AREusually simplified by cancellation (ie. Mg4C2 becomes Mg2C) • Why? Because the bonding pattern is not as important between ions as it is in molecules. What is important is the ratio of ions.

  32. Quick Exercise (binary ionic)do on lined paper • What is the systematic name of each compound? • CaO Na2S CaF2 • Al2O3 MgBr2 Ca3N2 • K3N Li4C BeCl2 • What is the formula of: • Lithium oxide barium nitride • Calcium fluoride sodium phosphide • Aluminum sulphide calcium sulphide • Magnesium carbide lithium chloride Calcium oxide sodium sulphide calcium fluoride Aluminum oxide magnesium bromide calcium nitride Potassium nitride lithium carbide beryllium chloride Li2O Ba3N2 CaF2 Na3P Al2S3 CaS Mg2C LiCl

  33. The Ionic RulesTernary Ionic Compound • Ternary ionic compounds contain 3 or more elements • Their systematic names often end in either –ate or –ite. • They always include a polyatomic ion (also called a radical)

  34. Some polyatomic ions • OH- hydroxide H- hydride • CO32- carbonate HCO32- bicarbonate* • SO42- sulfate (sulphate) SO32- sulfite (sulphite) • PO43- phosphate PO33- phosphite • ClO31- chlorate ClO21- chlorite • NO31- nitrate NO21- nitrite • NH4+ ammonium CN- cyanide • See more radicals on page 97of textbook • * A.K.A. hydrogen carbonate (the term “bi” was once used to indicate a hydrogen atom in the radical)

  35. Finding Formulas from Names • Binary covalent (molecular) formulas • Use the name as a guide • Binary ionic formulas • Use the “crossover” rule (or balance charges) • Ternary ionic formulas • Find the charge of the polyatomic ions. • Then use the “crossover” rule. • Ternary covalent compounds (organic) • A separate, complex systems of names is used (not studied in detail this year) FYI: A few organic-covalent compounds can be known by two or more different names, for example, CH4 can be called carbon tetrahydride (its systematic name) or methane (its organic name). Since methane is shorter, most people use that name. Also NH3 can be called nitrogen trihydride (systematic name) or ammonia (the name used for an NH3 group in organic chemistry)

  36. Quick Exercise (ternary ionic)do on lined paper • What is the formula of • Calcium carbonate potassium cyanide • Sodium phosphate barium phosphate • Magnesium nitrate aluminum sulfate • What is the name of • AgNO3 NH4CN • Na2CO3 (NH4)3Cr2O7 • Na2SiO3 KMnO4 • CsHCO3 Al(NO2)3 CaCO3 Na3PO4 Mg(NO3)2 KCN Ba3(PO4)2 Al2(SO4)3 Silver Nitrate Sodium carbonate Sodium silicate Cesium bicarbonate Ammonium cyanide Ammonium dichromate Potassium permanganate Aluminum nitrite

  37. The Organic Rules • You don’t need to know the organic rules FYI: The names of organic compounds are based on the hydrocarbons: methane (1C), ethane(2C), propane(3C), butane(4C), pentane(5C), hexane(6C), heptane(7C), octane(8C), etc. combined with a lot of descriptive endings. Thus an alcohol with one carbon is called methanol, an alcohol with 2 carbons is ethanol, and so on. Further complicating this is that some traditional names are given to organic compounds that don’t match the system above, so there is a lot of memory work involved in assigning names to organic compounds.

  38. Alkanes: the simplest example of organic compound naming. • Alkanes are chains of carbon atoms with hydrogen atoms attached, with the general formula CxH2x+2 • CH4 = methane C8H18 = octane • C2H6= ethane C12H26 = dodecane • C3H8= propane C13H28 = tridecane • C4H10=butane C20H42 = eicosane • C5H12= pentane C23H48 = tricosane

  39. For example, the molecule shown below is called: 18-bromo-12-butyl-11-chloro-4,8-diethyl-5-hydroxy-15-methoxytricos-6,13-dien-19-yne-3,9-dione

  40. Polyvalent elements • Some elements have more than one possible valence • Transition elements in particular are this way (but there are a few representative elements that do this too). • For example, copper can be Cu1+ or Cu2+. • In the old days, Cu1+ was called “cuprous copper” and Cu2+ was called “cupric copper”, but this system proved confusing. (the old system is called the classical name) • Now, Cu1+ is called Copper(I) and Cu2+ is called Copper(II), but some chemists still use the old names. (the new system is called the stock name) • See the chart on page 95 for other examples

  41. Classical Names and the metals they are associated with metal lower oxidation state higher oxidation state • Copper cuprous 1+ cupric 2+ • Iron ferrous 2+ ferric 3+ • Mercury mercurous 1+ mercuric 2+ • Lead plumbous 2+ plumbic 4+ • Tin stannous 2+ stannic 4+ • Chromium chromous 2+ chromic 3+ • Manganese manganous 2+ manganic 3+ • Cobalt cobaltous 2+ cobaltic 3+ Copper(I) 1+ Copper(II) 2+ Iron(II) 2+ Iron(III) 3+ Mercury(I) 1+ Mercury(II) 2+ Lead(II) 2+ Lead(IV) 4+ Tin(II) 2+ Tin(IV) 4+ Chromium(II) 2+ Chromium(III) 3+ Manganese(II) 2+ Manganese(III) 3+ Cobalt(II) 2+ Cobalt(III) 3+

  42. YES YES YES YES YES YES YES YES Eight questions that can identify which rules to use from a compound’s formula • Is it a common exception? H2O, H2O2 • Does the formula begin with H? • Does it end with COOH? • Does it end with CH2OH? • Does it end with OH? • Does it end with a radical? • Does it begin with a metal? • Does it begin with NH4? Covalent (exceptions) acid Ionic Organic acid Org alcohol Org base Ionic ternary Ionic* salt Ionic Ammonium salt Ionic* NO You must ask these two question before Asking the next one! covalent

  43. Textbook Exercise • Page 110 #18 to 32

  44. Summary of Rules for Naming Covalent Compounds • Covalent Compounds contain NO metals. • They don’t start with H or NH4 either. • Names end in “-ide” • Names depend on formulas • Use prefixes to indicate #atoms of each element • mon(o) =1 penta = 5 • di = 2 hexa = 6 • tri = 3 hepta =7 • tetra = 4 oct(o) = 8 • Examples: carbon dioxide: CO2 carbon monoxide: CO carbon tetrachloride: CCl4 diphosphorus pentoxide: P2O5 sulfur hexafluoride: SF6

  45. Summary of Rules for Binary Ionic Compounds • Binary Ionic Compounds contain a metal and a non-metal • Names do not contain prefixes • Metal name goes first, followed by non-metal, with ending changed to “-ide” • If the metal is polyvalent, insert a roman numeral in brackets to give its valence. • Examples sodium oxide: Na2O calcium chloride: CaCl2 copper(II)oxide: CuO iron(III)oxide: Fe2O3 -To find a formula from the name, use CROSSOVER.

  46. Name Rules for Ternary Ionic Compounds • Ternary Ionic Compounds always contain a radical(A.K.A. polyatomic ion) • Names do not contain prefixes • Name of the metal is followed by the name of the radical part. • Exception: If the radical is ammonium (NH4) then it goes first! • Examples: sodium carbonate: NaCO3 calcium hydroxide: Ca(OH)2 ammonium sulfite: (NH4)2SO3 copper(II)phospate: Cu3(PO4)2 -To find a formula from the name, use CROSSOVER.

  47. The Eight Questions • Is it water (H2O)? covalent • Does the formula begin with H? ionic • Does it end with COOH? ionic • Does it end with CH2OH? covalent • Does it end with OH? ionic • Does it end with a radical? ionic • Does it begin with a metal? ionic • Does it begin with NH4? ionic • It has only non-metals covalent

  48. Quick Exercise Give the formula of each of the compounds named below Indicate if the compound is Covalent or Ionic Then give the systematic name. C C I I It It I It I C N2S5 carbon tetrafluoride SO2 diphosphorus trisulfide Na2S calcium bromide Li3N iron(III)sulfide Ca(NO3)2 iron(II)sulfide Na2SO4 magnesium hydroxide Mg3P2 nitrogen trichloride AlPO4 phosphorus pentoxide BeCl2 ammonium sulfide NF3 magnesuium phosphate Dinitrogen pentasulfide Sulfur dioxide Sodium sulfide Lithium nitride Calcium nitrate Sodium sulfate magnesium phosphide Aluminum phosphate Beryllium chloride Nitrogen trifluoride CF4 P2S3 CaBr2 Fe2S3 FeS Mg(OH)2 NCl3 PO5 (NH4)2S Mg3(PO4)2

  49. Answers to Ex. P.110 • 18. Classify the elements: • a) Al = metal b) Ag = metal c) Si = metalloid d) He = non-metal e) Zn = metal • 19. Which groups do they belong to? • A) Aluminum = other metals (or group IIIA or boron fam.) • B) Silver = transition metals (or group IB or coin metals) • C) Silicon = metalloids (or group IVA or carbon family) • D) Helium = noble gases (or Inert gases or group VIIIA) • E) Zinc = transition metals (or group IIB) • 20. State the electrons gained or lost: • a) S2- = gain 2 d) Ba2+ =lost 2 • b) K+ = lost 1 e) Li+ = lost 1 • c) Cl- = gain 1 f) H- = gain 1

  50. 21. Name and identify the ions in Q.20 • A) S2-sulphide ion: anion • B) K+potassium ion: cation • C) chloride ion: anion • D) barium ion: cation • E) lithium ion: cation • F) hydride ion: anion • 22. Ionic or molecular? • A) CO = molecular* C) C3H8 = molecular* • B) KBr = ionic D) SO3 = molecular* * here molecular means the same as covalent, so you could answer “

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