Nomenclature. Na Na + + e. Cl + e - Cl - 2/24/2014. Symbols for Atoms, Molecules, and Ions. Molecules and Ions. Isotope form:

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1 Symbols for Atoms, Molecules, and Ions Nomenclature Isotope form: CHEMISTRY 11 The top number represents the mass number. 4 2He The bottom number represents the atomic number. Molecules and Ions Recall: The bottom number is always the number of protons. The bottom number is also usually the number of electrons, but only in a neutral element. The number of neutrons is always the top number minus the bottom number. Compounds are made up of two or more atoms held together 2 different methods: 1. Both sharing electrons (produces a MOLECULE having covalent bonds). Take water for example: Each H shares its electron with the O, so that the O has two shared electrons, completing its valence shell. 2. One taking electrons from the other (produces an IONIC SALT or FORMULA UNIT having ionic bonds). Consider NaCl: Chlorine has a higher affinity for electrons than Sodium, and so it takes one away as shown by the following: Cl + e - Cl - The electron joins up with the chlorine, and becomes a negatively charged ion (also known as an ANION). The electron came from the sodium atom: Na Na + + e The normal Sodium atom gives off an electron and becomes a positively charged ion in the process (also known as a CATION). Since these charges have opposite signs, they attract to form the ionic solid. 1

2 Review of Naming Ions don't have to be just one atom; they can be polyatomic (consisting of many atoms). For Example: From Science 10 Honours Naming: Ionic Compounds Binary and Polyatomic Hydrates Multivalent Cations Using Stock Method and Common Name Covalent Compounds Acids and Bases Counting Atoms Ionic Compounds Again, with multivalent cations Name Formula Compound Common Name Stock Name Mg(OH) 2 Magnesium hydroxide Aluminum chloride AlCl 3 Sodium sulphide Na 2 S Fe 2 O 3 Ferric oxide Iron (III) oxide (NH 4 ) 2 SO 4 Ammonium sulphate NaClO Sodium hypochlorite Potassium oxide K 2 O CrF 2 Chromous fluoride Chromium (II) fluoride CuCl 2 Cupric chloride Copper (II) chloride Magnesium hydride MgH 2 Ca(HCO 3 ) 2 KHC 2 O 4 Calcium bicarbonate Potassium binoxalate Hydrates? Dissociation of Ionic Salts Electrolyte: You know the drill Iron (III) phosphate octahydrate Nickel (II) chloride hexahydrate Calcium nitrate tetrahydrate FePO 4 8H 2 O NiCl 2 6H 2 O Ca(NO 3 ) 2 4H 2 O A substance which dissolves to give an electrically conducting solution containing ions. Produced from an ionic salt. For example: Sodium sulphate decahydrate Na 2 SO 4 10H 2 O Magnesium hydrogen phosphate heptahydrate MgHPO 4 7H 2 O (NH 4 ) 2 SO 4(s) è 2 NH 4 + (aq) + SO 4 2- (aq) Nickel (II) phosphate octahydrate Ni 3 (PO 4 ) 2 8H 2 O Dissociation equation: salt è ions. 2

3 NO dissociation for covalent! Try some covalent you ll be better for it! Tetraphosphorus trisulphide P 4 S 3 Trisilicon tetranitride Si 3 N 4 Oxygen diflouride OF 2 Bromine monofluoride BrF Tetrasulphur dinitride S 4 N 2 Diphosphorus hexaoxide P 2 O 6 Molecular: Compounds made up of a non-metal and a non-metal will be molecular in solution (do not form ions, stay as a molecule in solution). For example: CH 3 OH (l) è CH 3 OH (aq) Usually organic compounds (more to come later). Beware of acetate (CH 3 COO - ) and other organic ions. They will form ionic solutions. And last, but not least, ACIDS!!! Counting Atoms remember? Name Formula Hydrochloric Acid HCl Nitric Acid HNO 3 Sulphurous Acid H 2 SO 3 Chlorous Acid HClO 2 When we are given a molecule, it s easy to count how many atoms are present. For Example: AgNO 3(s) 5 atoms KCl (aq) 2 atoms Pb(SO 4 ) 2(s) 11 atoms Al(CH 3 COO) 3(s) 22 atoms Transition metals (a.k.a. The Weirdo's ) Exhibit the following characteristics: Form more than one oxidation state (charge). The cations are often complex ions. The transition metal is surrounded by a certain number of LIGANDS (molecules or ions that bond to a metal ion). For example: Unlike other metals, transition metals show great similarities within a given period and group. [Co(NH 3 ) 6 ]Cl 3 3

4 Coordination Compounds Most compounds produce coloured solutions. Formed by transition metal ions. Consists of a (a transition metal with its attached ligands) and (ions to balance out charge). For example: [Co(NH 3 ) 5 Cl]Cl 2 Ligands When these compounds dissolve in water, they usually produce coloured solutions that act as ionic compounds: [Co(NH 3 ) 5 Cl]Cl 2(s) Co(NH 3 ) 5 Cl 2 + (aq) + 2Cl - (aq) A neutral molecule or ion having a lone electron pair that can be used to form a bond to a metal ion. Monodentate Ligand: Also called unidentate ligand. Can form one bond to a metal ion. Bidentate Ligand: Can form two bonds to a metal ion. Chelating Ligand or Chelates: A ligand that is attached to a central metal ion by bonds from two or more donor atoms. Coordination Number The number of bonds formed by metal ions to ligands varies from two to sixteen. Depends upon the size, charge, and electron configuration of the transition metal ion. Chelating ligand Each coordination number will produce a different geometry (more to come later). 4

5 Nomenclature For Example: For each of the following, determine the coordination number: [Zn(NH 3 ) 4 ] 2+ [Co(CN) 6 ] 3- [Ag(NH 3 ) 2 ] + Name these [Cr(NH 3 ) 3 (H 2 O) 3 ]Cl 3 triamminetriaquachromium(iii) chloride [Pt(NH 3 ) 5 Cl]Br 3 pentaamminechloroplatinum(iv) bromide [Pt(H 2 NCH 2 CH 2 NH 2 ) 2 Cl 2 ]Cl 2 dichlorobis(ethylenediamine)platinum(iv) chloride [Co(H 2 NCH 2 CH 2 NH 2 ) 3 ] 2 (SO 4 ) 3 tris(ethylenediamine)cobalt(iii) sulfate K 4 [Fe(CN) 6 ] potassium hexacyanoferrate(ii) Na 2 [NiCl 4 ] sodium tetrachloronickelate(ii) Write the formulas for the following: Homework: Hexaammineiron(III) nitrate [Fe(NH 3 ) 6 ](NO 3 ) 3 Ammonium tetrachlorocuprate(ii) (NH 4 ) 2 [CuCl 4 ] Sodium chloropentacyanoferrate(iii) Na 3 [Fe(CN) 5 Cl] Potassium hexafluorocobaltate(iii) K 3 [CoF 6 ] Do: Nomenclature Study for your quiz (in two classes)!!! Naming Compounds 5

6 What is on the exam? The Classification of Matter Atoms, Molecules, and Ions Classifying Matter Heterogeneous, Homogeneous, etc. The Physical Separation of Substances Distillation, Chromatography, etc. Nomenclature Symbols for atoms, ions, and molecules Naming and Formulas for: Ionic Compounds Covalent Compounds Hydrates Acids Complex Ions Counting Atoms 6