Chemistry 100(02) Fall 2012 Instructor: Dr. Upali Siriwardane Office: CTH 311 Phone Office Hours: M,W, 8:00-9:00 & 11:00-12:00 a.m Tu,Th,F 9: :00 a.m. Test Dates : October 1, 2012 (Test 1): Chapter 1 & 2 October 22, 2012 (Test 2): Chapter 3 & 4 November 14, 2012 (Test 3) Chapter 5 & 6 November 15, 2012 (Make-up test) comprehensive: Chapters 1-6 9:30-10:45:15 AM, CTH 328 CHEM 100, Fall 2012 LA TECH 2-1

REQUIRED : Textbook: Principles of Chemistry: A Molecular Approach, 2nd Edition-Nivaldo J. Tro - Pearson Prentice Hall and also purchase the Mastering Chemistry Group Homework, Slides and Exam review guides and sample exam questions are available online: and follow the course information links. OPTIONAL : Study Guide: Chemistry: A Molecular Approach, 2nd Edition- Nivaldo J. Tro 2nd Edition Student Solutions Manual: Chemistry: A Molecular Approach, 2nd Edition-Nivaldo J. Tro 2nd Text Book & Resources CHEM 100, Fall 2012 LA TECH 2-2

Chapter 3. Molecules, Compounds, and Chemical Equations 3.1 Hydrogen, Oxygen, and Water Chemical Bonds Representing Compounds: Chemical Formulas and Molecular Models An Atomic-Level View of Elements and Compounds Ionic Compounds: Formulas and Names Molecular Compounds: Formulas and Names Formula Mass and the Mole Concept for Compounds Composition of Compounds Determining a Chemical Formula from Experimental Data Writing and Balancing Chemical Equations Organic Compounds 114 CHEM 100, Fall 2012 LA TECH 2-3

Chapter 3. KEY CONCEPTS  Writing Molecular and Empirical Formulas (3.3)  Classifying Substances as Atomic Elements, Molecular Elements, Molecular Compounds, or Ionic Compounds (3.4)  Writing Formulas for Ionic Compounds (3.5)  Naming Simple Ionic Compounds (3.5)  Naming Ionic Compounds Containing Polyatomic Ions (3.5)  Naming Molecular Compounds (3.6)  Naming Acids (3.6)  Calculating Formula Mass (3.7)  Using Formula Mass to Count Molecules by Weighing (3.7)  Calculating Mass Percent Composition (3.8)  Using Mass Percent Composition as a Conversion Factor (3.8)  Using Chemical Formulas as Conversion Factors (3.8)  Obtaining an Empirical Formula from Experimental Data (3.9)  Calculating a Molecular Formula from an Empirical Formula and Molar Mass (3.9)  Obtaining an Empirical Formula from Combustion Analysis (3.9)  Balancing Chemical Equations (3.10) CHEM 100, Fall 2012 LA TECH 2-4

Intramol ecular Chemical Bonding Types onic : Complete transfer of 1 or more electrons from one atom to another, usually between a metal and a nonmetal element Covalent: The sharing of val ence electrons shared between nonmetal elements Metallic: The communal sharing of electrons between metals * Note: Most molecular bonds are actually somewhere in between covalent and ionic types. CHEM 100, Fall 2012 LA TECH 2-5

MOLECULAR Nonmetals only0 IONIC Metal and n o nm etal ACIDS* H and one or more nonmetals -■ ■.- prefix name of prefix 1st element l base name of 2nd element + -ide Example: P 2 0, diphosphorus pentoxide Metal forms more than one type of ion name of cation (metal) base name of anion (nonmetal) + -ide Example: Cali calcium iodide 1 - Oxyacids Contain oxygen base name of oxyanion + -ic —,0 4 / Example: H 1 PO 4 phosphoric acid Binary acids Two-element base name of anion (nonmetal) + - ide hydro 01■0. 4„. acid name of cation (metal) _■/".1 charge of cation (metal) in Roman numerals in parentheses base name name of nonmetal + -ic s- acid A.- 1 base name of oxyanion [ + -ous Example: FeCI Example 1-1C1(aq) Example: H 2 SWaq) iron(in) chloride hydrochloric acid sulfurous acid *Acids must be in aqueous solution. CHEM 100, Fall 2012 LA TECH 2-6

Types of Compounds ar or Covalent Compounds: B) Mo lecul non-metal + non-metal nonmetaloxide or halides: SO 2 Organic compounds: C 3 H 8 CHEM 100, Fall 2012 LA TECH 2-7

MOLECULAR ACIDS* Nonmetal H and one or 4 14_ only more nonmetals Binary acids Two-element Oxyacids Contain oxygen base n ame of oxyanion + -k Example, II 3 PO4 phospliovi( acid T base name of prefix 2nd element + -ide name of 1st element prefix (xiimplc:1) ;,0 5 diphosphorus pentoxide CHEM 100, Fall 2012 LA TECH Example'. HiS03(aq) sulfurous acid *Acids mug be in aqueous base Dame of nonmetal -ic Example; HCI(ao) hydrochloric acid 2-8

CHEMICAL BONDS: THE FORCE BETWEEN ATOMS What Makes a Molecule? Structural formula Space-filling model H H C H H Methane, CH Pearson Educalwrt Inc CHEM 100, Fall 2012 LA TECH 2-9

Molecular Compounds: Nonmetal Name the most “metallic” of the nonmetals first. + Nonmetal Change the ending of the nonmetal to “ IDE. ” Indicate the number of atoms of the nonmetal by Latin prefixes.  Mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca  Examples: – P 2 O 5 : diphosphorous pentaoxide – CO: carbon monoxide CHEM 100, Fall 2012 LA TECH 2-10

For compounds composed of two non-metallic e ements, the more metallic element is listed first. To designate the multiplicity of an el ement, Greek prefixes are used: mono  1; di  2; tri  3; tetra  4; penta  5; hexa  6; hepta  7; octa  8 Naming Binary Molecu lar-Coval ent Compounds CHEM 100, Fall 2012 LA TECH 2-11

1) H 2 O, Na 3 PO 4, HCl, C2H6, NH 3, KCl, CH 4, NH 4 Cl, C6H12O6, Brass- Cu x Zn y, SO 3, NaCl, CO 2 Identify the types of compounds in the above list: Molecular compound: Ionic compound: Alloy: Organic: Inorganic: CHEM 100, Fall 2012 LA TECH 2-12

H 2 O, Na 3 PO 4, HCl, C2H6, NH 3, KCl, CH 4, NH 4 Cl, C6H12O6, Brass- Cu x Zn y, SO 3, NaCl, CO 2 2) Which of the above compounds have Molecular formula: Ionic formula: Distinct empirical formula: CHEM 100, Fall 2012 LA TECH 2-13

3) Indicating the type and number of atoms in a molecule of the covalent compound: C 6 H 12 O 6. a.C: b.H: c.O: d.Molecular formula: e.Empirical formula: CHEM 100, Fall 2012 LA TECH 2-14

Simple Binary Molecular Compounds H 2 O water (common name) NH 3 ammonia (common name ) N 2 O dinitrogen oxide (nitrous oxide) NO nitrogen monoxide (nitric oxide) NO 2 nitrogen dioxide N 2 O 4 dinitrogen tetroxide CO carbon monoxide CS 2 carbon disulfide SO 3 sulfur trioxide CCl 4 carbon tetrachloride PCl 5 phosphorus pentachlorid e 2-15 SF 6 sulfur hexafluoride CHEM 100, Fall 2012 LA TECH

4) Give systematic names to following binary inorganic molecular compounds a) H 2 O: b) HCl: c) SF 6 : d) BF 3 : e) N 2 O 4 : f) CCl 4 : g) SO 3 : h) PCl 3 : CHEM 100, Fall 2012 LA TECH 2-16

alkanes – C n H 2n+2 E.g. C5H12 pentane alkenes – C n H 2n E.g. C 2 H 4 ethene alkynes – C n H 2n-2 E.g. C 2 H 2 ethyne alcohols – ROH E.g C 2 H 5 OH ethanol Hydrocarbons and Alcohols where R refers to the hydrocarbon radical backbone created by substituting an -OH functional group for aH atom in the hydrocarbon 2-17 CHEM 100, Fall 2012 LA TECH

5) Give the common name of the following molecular compounds a.NH 3 : b.CH 3 COOH: c.C 6 H 12 O 6 : d.C 2 H 5 OH: CHEM 100, Fall 2012 LA TECH 2-18

Acids Types of acids  Binary acids  H + and nonmetal anion In aqueous solutions, acids contain the H + cation and  Oxyacids  H + cation and polyatomic anion anion CHEM 100, Fall 2012 LA TECH

Naming Acids Formula starts with H HCl Hydrochloric acid HNO 3 Nitric acid H 2 SO 4 Sulfuric acid HClO 3 Chloric acid 2-20 H 3 BO 3 Boric acid H 3 PO 4 Phosphoric acid CHEM 100, Fall 2012 LA TECH

Names of acids and ions HClO 2 chlorous ClO 2 ¯ chl HClO 3 chloric ClO 3 ¯ chl HClO 4 perchloric ClO 4 ¯ perchl HNO 3 nitric NO 3 ¯ nitrate CHEM 100, Fall 2012 LA TECH HClO hypochlorous HNO 2 nitrous NO 2 ¯ nitrite ClO ¯ ”hypochlorite orate orite orate 2-21

formula ends with OH Naming bases NaOH Ba(OH) 2 barium hydroxid KOH sodium hydroxid potassium hydroxid e e e 2-22 Ca(OH) 2 calcium hyd NH 4 OH roxide ammonium hydroxid e CHEM 100, Fall 2012 LA TECH

6) Give the names of the following acids FormulaNameIon (s)FormulaNameIons(s) a) HNO 3 : b) H 3 PO 4 : c) HNO 2 : d) H 3 PO 3 : e) H 2 SO 4 : f) H 2 CO 3 : g) H 2 SO 3 : h) CH 3 COOH: CHEM 100, Fall 2012 LA TECH 2-23

Types of Chemical Formula Molecular Shows ratio of atoms each element in the : C 2 H 6 O Condensed Shows groups of atoms bonded together in the formula.E.g ethylalcohol: CH 3 CH 2 OH Structural Shows bonding of important groups in the formu E.g ethylacohol: a 2-24 compound.E.g ethylalcohol CHEM 100, Fall 2012 LA TECH

2-25 Models of Ethanol CHEM 100, Fall 2012 LA TECH

7) Given the structural formula of an organic compound, write the for the following: CH 3 CHClCH 2 OH a.molecular formula b.condensed formula c.structural formula d.line formula CHEM 100, Fall 2012 LA TECH 2-26

2-27 Catenation The formation of chains of atoms of the same This key feature of carbon permits a vast number of compounds to exist. Four types of hydrocarbons 1.Alkanes (saturated): single C-C bonds 2.Alkenes (unsaturated): double C=C bond 3.Alkynes (unsaturated): triple bond 4.Aromatic (unsaturated): benzene rings Hyd eement. rocarbons CHEM 100, Fall 2012 LA TECH

Alkanes C n H 2n+2 methane – CH 4 ethane – C 2 H 6 propane – C 3 H 8 butane – C 4 H 10 pentane – C 5 H 12 hexane – C 6 H 14 heptane – C 7 H 16 octane – C 8 H 18 nonane – C 9 H 20 decane – C 10 H 22 CHEM 100, Fall 2012 LA TECH 2-28

Base names of hydrocarbons Prefix Carbons Meth- 1 Eth- 2 Prop- 3 But- 4 Pent- 5 Hex- 6 Hept- 7 Oct Dec I see much memorization in your future! Non CHEM 100, Fall 2012 LA TECH

8) Name, molecular, condensed and line formula of straight chain alkane (saturated hydrocarbons) or n-alkanes. a.4 carbon n-alkane: b.7 carbon n-alkane: CHEM 100, Fall 2012 LA TECH 2-30

What is an Isomer? Compounds with the same number and type of atoms but with different arrangements are called constitutional isomers Condensed formul Molecul ar Formula C 5 H 12 as. CH 3 CH 2 CH 2 CH 2 CH 3 pentane CH 3 CH(CH 3 )CH 2 CH 3 2-methylbutane (CH 3 ) 4 C 2,2-dimethylpropane All are isomers of C 5 H 12. CHEM 100, Fall 2012 LA TECH 2-31

Alkane Isomers is there a formula? Molecular Number of Formula Isomers CH4 1 C2H6 C 3 H 8 1 C4Hio 2 C C C C C9H20 C Cl2H26 C C C 30H62 C40H , ,319 4,111,846,763 62,491,178,805,831 CHEM 100, Fall 2012 LA TECH 2-32

9) Draw the structural formula of constitutional isomers of butane with molecular formula C 4 H 10. a.n-butane: CH 3 CH 2 CH 2 CH 3 b.isobutene: (CH 3 ) 3 CH CHEM 100, Fall 2012 LA TECH 2-33

2-34 Butane Butane molecules are present in the liquid and gaseous states in the lighter CHEM 100, Fall 2012 LA TECH

Determine empirical formulas for the following: 1. An ionic compound that has two aluminum ions for every three oxide ions 2.Hexane, C 6 H 14 1.Arabinose, C 5 H 10 O 5 2.Hydrogen peroxide, Al 2 O 3 (C 3 H 7 ) n where n = 2 (CH 2 O) n where n = 2 (HO) n where n = 2 CHEM 100, Fall 2012 LA TECH 2-35

Classifying Organic Compound s Examples Functional Group Ending Hydrocarbons C and H only -ane Alcohols R-OH -ol Acids R-COOH Amines R-NH 2 -amine Ketones R(C=O)R ’ -one Aldehydes R-CHO -al -oic acid CHEM 100, Fall 2012 LA TECH 2-36

10) Classification and the name of the following g pg p ClassificationName a. CnH2n+2 where n is 8: a.CH 3 CH 2 CH 2 CH 2 -OH: a.CH 3 CH 2 CH 2 -COOH: a.CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 -NH 2 : a.CH 3 CH 2 -(C=O)-CH 3 : d) CH 3 CH 2 -CHO: CHEM 100, Fall 2012 LA TECH 2-37

The Many Representations of a Molecule TABLE 3.1 Benzene, Acetylene, Glucose, and Ammonia Name of Empirical Molecular Structural Compound Formula Formula Formula Ball - and - Stick Model Space - Filling Model Benzene CH C 6 H 6 H 'C' C,H II H Acetylene CH C2H Glucose CH 2 O C6H CH H— C —OH HO—C—H H— C —OH H—C —OH OH Ammonia CHEM 100, F—.. _ NH 3 H a

11) Identify the classification or name of the following biologically important molecules a)b)c) d)e)f) CHEM 100, Fall 2012 LA TECH 2-39