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Atoms_ Molecules_ Ions_ and Inorganic Nomenclature - PowerPoint

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					Atoms, Molecules, Ions, and
  Inorganic Nomenclature

       Brown, LeMay Ch 2
          AP Chemistry
     Monta Vista High School
2.2: Evidence for the Atomic Theory
1. J.J. Thomson’s cathode ray tube: discovery of
   electrons and the e- charge-to-mass ratio
   In a vacuum chamber, flow of high voltage (emitted
    from cathode to anode) is deflected by magnetic &
    electrical fields




                                                         2
2. Robert Millikan’s oil drop: determines charge of
   e- (and thus the mass)
   “Atomized” drops of oil picked up small charges (integral
    numbers), and balanced oil drops in an electrical &
    gravitational field
3. Ernest Rutherford’s gold foil: discovery of
   nucleus as center of positive charge
   Alpha particles from
    radioactive source are
    deflected from positive gold
    atom nuclei
      2.3: Structure of the Atom
Figure 1: Subatomic particles (Table 2.1; 1 amu =
1.66054 x 10-24 g).
Subatomic
                 Charge       Location        Mass
 particle

Proton, p+ +1.6 x 10-19 C nucleus        1.0073 amu

Neutron, n       None         nucleus    1.0087 amu

Electron, e- -1.6 x 10-19 C   e- cloud   5.486 x 10-4 amu

                                                        5
                     Vocabulary
   Atomic number: number of p+ (determines the
    element)
   Mass number: sum of p+ and n (determines the
    isotope)
   Isotopes: atoms of an element that differ in the
    number of neutrons
   Groups or families: columns on Periodic Table:
    alkali (1A), alkaline earth (2A), halogens (7A), noble
    or inert gases (8A); pnictogens (5A) and chalcogens
    (6A); have same number of valence e-
   Periods: rows on P.T.; indicates new shell of e-
   Cations: positively charged ions
   Anions: negatively charged ions                        6
Figure 2: Inorganic nomenclature; commonly used but not
easily predictable cations
                +4 cations                          +3 cations

Lead (IV) or plumbic         Pb4+ Antimony (III) or antimonous   Sb3+

Tin (IV) or stannic          Sn4+ Arsenic (III) or arsenous      As3+
Titanium (IV)                Ti4+   Bismuth (III)                Bi3+
                                    Chromium (III) or chromic    Cr3+
                                    Cobalt (III) or cobaltic     Co3+
                                    Gold (III) or auric          Au3+
                                    Iron (III) or ferric         Fe3+
                                    Titanium (III)               Ti3+
Figure 2: Inorganic nomenclature; commonly used but not
easily predictable cations
             +2 cations                         +1 cations

Cadmium                    Cd2+    Ammonium                  NH4+

Cobalt (II) or cobaltous   Co2+    Copper (I) or cuprous     Cu+

Copper (II) or cupric      Cu2+    Gold (I) or aurous        Au+

Iron (II) or ferrous       Fe2+    Hydronium                 H3O+

Lead (II) or plumbous      Pb2+    Silver                    Ag+

Mercury (I) or mercurous   Hg22+

Mercury (II) or mercuric   Hg2+

Nickel                     Ni2+

Tin (II) or stannous       Sn2+

Zinc                       Zn2+
Figure 3: Inorganic nomenclature; commonly used but not
easily predictable anions
            -3 anions                        -2 anions

Borate                  BO33-   Carbonate                 CO32-

Phosphate               PO43-   Chromate                 CrO42-

                                Dichromate               Cr2O72-

                                Oxalate                  C2O42-

                                Peroxide                  O22-
                                Selenate                 SeO42-

                                Sulfate                   SO42-
Figure 3: Inorganic nomenclature; commonly used but not
easily predictable anions
                             -1 anions

Acetate              C2H3O2- Isothiocyanate               CNS-
Bromate               BrO3-      Hydroxide                OH-
Chlorate              ClO3-      Nitrate                  NO3-
Cyanide                CN-       Permanganate         MnO4-
Hydride                 H-       Superoxide               O2-
Iodate                 IO3-      Thiocyanate              SCN-
                    Naming Compounds Flow Chart
                                          Does the formula start with H?
                                           NO                     YES

 Does it begin with a metal that has more than one                                    It is an acid (must be aqueous).
   oxidation number? (e.g. Fe, Ni, Cu, Sn, Hg)
   NO                                      YES
                                                                                  Does the acid contain a polyatomic ion?
                                                                                      NO                        YES
                           Name the first element followed by its
                           oxidation number (Roman Numeral) or
                             “old school” –ic or –ous endings.                                  Does the acid end with a
                                                                                                   polyatomic ion?
 Does the formula contain a polyatomic ion?                                                  –ite                     –ate
 NO                                   YES

 Are both elements nonmetals?           Name the first element, then                                 Name the polyatomic
NO                       YES             the polyatomic ion. If two                                 ion, replacing the –ate
                                         elements are present, name                                  ending with –ic. Add
                                        both, then the polyatomic ion                                   the word acid.
 Name the first element,                  (e.g. NaHCO3 is sodium
 Then the second element                    hydrogen carbonate).                               Name the polyatomic ion,
   with an –ide ending.
                                                                                               replacing the –ite ending
                                                                                               with –ous. Add the word
 Name the first element using the proper prefix (never
                                                                                                         acid.
   mono–). Name the second element with the proper
        prefix (including mono–) and –ide ending.
1 = mono– 4 = tetra–         7 = hepta– 10 = deca–                        Write the prefix hydro–, then the
2 = di–         5 = penta– 8 = octa–                                    name of the second element with –ic
3 = tri–        6 = hexa–    9 = nona– (not nano–)                          ending. Add the word acid.
             Naming Hydrates
   Name the compound, then the Greek prefix,
    and then add -hydrate.
    Ex:     CuSO4۰5 H2O
            copper (II) sulfate pentahydrate




                                                12
     Naming Oxyacids & Oxyanions
   Oxyacid: polyatomic acid that contains a nonmetal
    bonded to one or more oxygen atoms
    Figure 4: The “standard” oxyacids (___ic acids)
     H3BO3       H2CO3       HNO3      X         X
                    X        H3PO4   H2SO4    HClO3
                            H3AsO4   H2SeO4   HBrO3
                                       X       HIO3


    Also: H2CrO4 = chromic acid
                                                        13
   Oxyanions: polyatomic anions that contain a
    nonmetal bonded to one or more oxygen
    atoms.
Figure 5: Naming oxyacids and oxyanions
                                                               Oxida
         Oxyacids                     Oxyanions
                                                               -tion
    Example     Format            Example     Format
                                                                 #

Perchloric      Per_____ic acid Perchlorate,      per___ate     +7
acid, HClO4                     ClO4-
Chloric acid,   _____ic acid    Chlorate, ClO3- ___ate          +5
HClO3

Chlorous        _____ous acid   Chlorite, ClO2-   ___ite        +3
acid, HClO2
Hypochlorous Hypo_____ous       Hypochlorite,     hypo___ite    +1
acid. HClO   acid               ClO-
Figure 6: Complete for sulfur oxyacids & oxyanions.
                                                       Oxidation
           Oxyacid                  Oxyanion
                                                           #

(Persulfuric acid)   (H2S2O8) (Persulfate) (S2O82- )     (+7)


Sulfuric acid         H2SO4   Sulfate        SO42-        +6


Sulfurous acid        H2SO3   Sulfite        SO32-        +4


Hyposulfurous acid    H2SO2   Hyposulfite    SO22-        +2
  Other Oxyacids Patterns
H3PO4 phosphoric acid
H2PO41- dihydrogen phosphate
HPO42- hydrogen (or monohydrogen)
             phosphate
PO43- phosphate

H2CO3 carbonic acid
HCO31- hydrogen carbonate or bicarbonate
CO32- carbonate
                                           16
Lewis Structures of common ligands

 NH3                         CN-




 S2O32-                      SCN-



 H2O (not always included in formula, however)
   The golden-orange compound is CoCl3*6NH3
    while the purple compound only has 5
    ammonia molecules in the coordinated
    compound. As shown in the ball-and-stick
    model, the chlorides serve as counter ions to
    the cobalt/ammonia coordiation complex in
    the orange compound, while one of the
    ammonia molecules is replaced by Cl in the
    purple compound. In both cases, the
    coordination geometry is octahedral around
    Co.
                        Notation
   Write complexes in square brackets, with charge on outside
    Ex: Cu2+ (aq) + 4 NH3 (aq) → [Cu(NH3)4]2+ (aq)
                                                    2+
                      H




                                         :NH3
                       |
        Cu2+ (aq) + 4 :N ─ H (aq) →      Cu
                       |
                      H
               Coordination number
   Number of positions where a ligand can bond.
       Similar to oxidation state
   Each metal ion has a characteristic (i.e., typical)
    coordination number, which can be predicted
    according to crystal field theory.
      Ag+: coordination number = 2 (2 ligand bonding
       positions); results in a linear complex
       [Ag(NH3)2]+ (aq)                         +
                      H               H    H
                       |               |     |
         Ag+ (aq) + 2 :N ─ H (aq) → H─ N:Ag:N─H   (aq)
                       |               |    |
                      H               H    H
   Zn2+ & Cu2+: coordination number = 4; tetrahedral complex
    Ex: [Zn(H2O)4]2+ (aq)




   Pt2+: coordination number = 4; square planar complex (d8 e-
    structure)
    Ex: [Pt(CN)4]2- (aq)
   Al3+, Cr3+, and Fe3+: coordination number = 6;
    octahedral complex
    Ex: [Cr(NH3)5Cl]2+ (aq)
Is dependent on:
 Charge of ligand:
  Ni2+: 6 NH3 or 4 CN- (since CN- transfers more
  negative charge)




   Size of ligand:
    Fe3+: 6 F- or 4 Cl- (larger ions take up more space)
            24.3: Nomenclature
1. Name cation before anion; one or both may be a
   complex. (Follow standard nomenclature for non-
   complexes.)

2. Within each complex (neutral or ion), name all
   ligands before the metal.
     Name ligands in alphabetical order
     If more than one of the same ligand is present, use a
      numerical prefix: di, tri, tetra, penta, hexa, …
     Ignore numerical prefixes when alphabetizing.
      Neutral ligands: use the name of the molecule (with
       some exceptions)
       NH3 ammine-                H2O aqua-

      Anionic ligand: use suffix –o
       Br-    bromo-               CN-   cyano-
       Cl-    chloro-              OH-   hydroxo-

3. If the complex is an anion, use –ate suffix
      Record the oxidation number of the metal in parentheses
       (if appropriate).
    Ex: [Co(NH3)5Cl]Cl2 pentamminechlorocobalt (III) chloride
       Nomenclature practice
1. K4[Fe(CN)6] potassium hexacyanoferrate


2. [Cr(NH3)4(H2O)CN]Cl2
              tetrammineaquacyanochromium
              (III) chloride
3. Na[Al(OH)4] sodium tetrahydroxoaluminate

				
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