<p> AP Chemistry Name ______Period ___ Date ___/___/___ 2  Nomenclature of Acids N O T E S</p><p>Note: IF you have ANY trouble with this sections – this is the place to go!: http://www.chemteam.info/ChemTeamIndex.html (choose Nomenclature), in the book, sections 4-5, 6 (note: the weblinks have practice problems with answers!!!)</p><p>I. Using Symbols to Write Formulas: (2-1, 2-2)</p><p>A. Chemical formulas:</p><p>1. Formulas describe the ratio of atoms/ions in a substance or the number of atoms/ions in a single molecule of the substance</p><p>2. Subscripts tell you the number of each atom/ion in the formula (note: no subscript is used for 1)</p><p>. ex: NaCl, CH3COOH, CH4 </p><p>B. Types of formulas:</p><p>1. Elements: (see 2-1)</p><p> a. monatomic, ex: ______</p><p> b. diatomic, ex (list 7): ______</p><p> c. polyatomic, ex: (list 2) ______</p><p>2. Compounds: can be expressed as</p><p> a. simplest whole number ratio of atoms (ionic) CaCl2 </p><p> b. actual number of atoms in a molecule (covalent) CH3COOH</p><p>II. Types of Compounds </p><p>A. Identify components of compounds - Use the “staircase” on the periodic table (see Table 4-2, p 126)</p><p>1. left and below the “staircase”: metals? nonmetals? metalloids?</p><p>2. right and above the “staircase”: metals? nonmetals? metalloids?</p><p>3. along the “staircase”: metals? nonmetals? metalloids?</p><p>0150e7f4c4e6fab1dc47ee3263a0214a.doc 1 Marsden, Christine B. Step 1 in naming/writing formulas: Identify types of compounds</p><p>1. “Ionic” - Metal + Nonmetal (or polyatomic ion)</p><p> a. (note: always expressed as simplest ratio of ions - called “formula units”)</p><p> b. ex. NaCl, MgCl2, Al2(SO4)3 (why are these ionic?)</p><p>2. “Molecular” or “Covalent” - do not start with a metal!</p><p> a. formula expressed as actual number of each type of atom in the formula</p><p> b. ex. C6H6 (not CH), SiO2, CS2 </p><p>3. Which are ionic? Which are covalent? (see bottom of page for answers)1</p><p> a. b. c. SO2 CaCl2 N2O4 </p><p>III. Covalent compounds (don’t forget – start with a nonmetal!)</p><p>A. Naming Covalent (Molecular) Compounds: Formula to Name (p. 51, 142) Note we will only use the “traditional” method), http://www.chemteam.info/Nomenclature/Binary-Greek-FormulatoName.html </p><p>1. Some have common names (those below you need to know)</p><p>H2O: ______CH4 ______</p><p>NH3: ______CH3OH______</p><p>CH3COOH______</p><p>1 1) covalent, 2) ionic, 3) covalent, 4) ionic p. 2 2. Naming binary (containing two types of atoms) molecular compounds</p><p> remember: these compounds are identified by LACKING metals</p><p>3. Steps for naming: a. Name the elements in the same order they appear in the formula b. Drop the last syllable (or two!) of the second element and add “-ide” (see table 4-11)</p><p> element symbol element name as second element, name becomes (same as for ionic)</p><p>Cl chlorine</p><p>Br bromine</p><p>O oxygen</p><p>S sulfur</p><p>N nitrogen nitride</p><p>P phosphorus phosphide</p><p> c. Add prefixes to the name of each element to indicate the number of atoms of that element in the molecules  Prefixes: (see p. 142) </p><p>1 mono 4 6 9</p><p>2 5 7 10</p><p>3 6 8 </p><p>Note: for the first element, mono is not used (no prefix needed) 4. Examples See write at least 3 examples here:</p><p> p. 3 B. Writing Formulas for Covalent (Molecular) Compounds: Name to Formula (p. 51, 142) (http://www.chemteam.info/Nomenclature/Binary-Greek- NametoFormula.html )</p><p>1. Use the prefixes to determine the number of each atom</p><p>2. Examples: see link (above) write at least 3 here</p><p>Note: for covalent compounds, DO NOT reduce subscripts!!! Subscripts reflect the ACTUAL NUMBER of each type of atom in the molecule</p><p>Special note: With regard to acids: Acids are covalent compounds, but have special rules which we shall touch on later in the notes.</p><p> p. 4 IV. Ionic Compounds (Compounds with Metal + Nonmetal, or with polyatomic ion) *** Be sure to print out the list of polyatomic ions to know!!! ***</p><p>A. Writing formulas – ionic compounds (links: </p><p> http://www.chemteam.info/Nomenclature/Binary-Fixed- NametoFormula.html </p><p> http://www.chemteam.info/Nomenclature/Binary-Stock- NametoFormula.html </p><p> http://www.chemteam.info/Nomenclature/Binary-Comm- NametoFormula.html </p><p> http://www.chemteam.info/Nomenclature/Polyatomic- NametoFormula.html </p><p>1. First, we need to know about ions and their charges - </p><p> a. Metals – lose electrons to become + ions (cations)</p><p> Ca  Ca2+ Ca+2  Na  Na1+ or Na+ or Na+1</p><p> b. Ions formed from elements in groups 1 & 2 have +1 and +2 charges, respectively</p><p> Ba  Cs Note: Hydrogen can combine as a +1 with a nonmetal</p><p> c. Ions you need to remember (table 2-3): Ag Zn Al </p><p> d. If the metals are other transition metals, you need to be given a “hint” – called “Stock System”</p><p> Parentheses and Roman numerals used to indicate charge</p><p>(i) Copper (I)  Cu1+ (ii) Copper (II)  Cu2+</p><p> Also, common names are used (and should be memorized!)</p><p>Element Lower Oxidation State Higher Oxidation State Stock Name Common Name Stock Name Common Name +1,+2 Copper copper (I) cuprous copper (II) cupric +1, +2 Mercury* mercury (I) mercurous mercury (II) mercuric +2,+3 Iron iron (II) ferrous iron (III) ferric +2,+4 Tin tin (II) stannous tin (IV) stannic +2, +4 Lead lead (II) plumbous lead (IV) plumbic p. 5 2+ *Note: mercury (I) is actually a polyatomic ion: Hg2 , ex: mercury (I) fluoride Hg2F2</p><p> e. Nonmetals: based on family</p><p> Nonmetals: gain electrons to become – ions (anions)</p><p> Halogens (group 17): Cl  Cl1- </p><p> Oxygen group (group 16):O  O2- </p><p> Nitrogen group (group 15) N  N3-</p><p>Note: Hydrogen can combine as a –1 with a metal: ex NaH called sodium hydride</p><p> f. PAI – need to memorize!!!</p><p>2. To write formulas, combine the two charged particles in the lowest whole number ratio to give a net charge of 0. </p><p> Now, let’s write formulas (first, go to web link from above)</p><p> Don’t forget – we need to BALANCE the charge with the lowest whole number</p><p> lithium bromide iron(III) chloride</p><p> magnesium oxide copper(II) sulfide</p><p> calcium nitride tin(IV) iodide</p><p> aluminum sulfide aluminum hydroxide</p><p> mercurous chloride calcium acetate</p><p> stannic fluoride potassium permanganate</p><p>B. Naming – ionic compounds (see </p><p> http://www.chemteam.info/Nomenclature/Binary-Fixed- FormulatoName.html</p><p> http://www.chemteam.info/Nomenclature/Binary-Stock- FormulatoName.html p. 6  http://www.chemteam.info/Nomenclature/Binary-Comm- FormulatoName.html </p><p> http://www.chemteam.info/Nomenclature/Polyatomic- FormulatoName.html </p><p>1. Cation</p><p> a. Metal: If only one possible charge, then just name it</p><p> b. If transition metal (and not silver or zinc), need to </p><p> determine charge (Figure out what charge it would need in order to balance the charge in the formula)</p><p>(i) FeCl3 (ii) Mn2O7</p><p> name using Stock system or common name (Stock is preferable)</p><p> c. + If polyatomic ion (usually NH4 ), just name it</p><p>2. Anion</p><p> a. Nonmetal – change the ending to –ide</p><p> b. Polyatomic ion – just name it</p><p>3. Examples: </p><p> a. Ca3N2 b. AuCl</p><p> p. 7</p>