3-1 CHEM 100, FALL 2011, LA TECH 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 : March 25, April 26, and May 18; Comprehensive Fina Exam: 9:30-10:45 am, CTH 328. Chemistry 100(02) Fall 2011 October 3, 2011 (Test 1): Chapter 1 & 2 October 26, 2011 (Test 3): Chapter 3 & 4 November 16, 2011 (Chapter 5 & 6) November 17, 2011 (Make-up test) comprehensive: Chapters 1-6 9:30-10:45:15 AM, CTH 328

3-2 CHEM 100, FALL 2011, LA TECH Chapter 3. Chemical Compounds 3.1 Molecular Compounds Page Naming Binary Inorganic Compounds Page Hydrocarbons Alkane and Their Isomers Page Ions and Ionic Compounds Page Naming Ions and Ionic Compounds Page Properties of Ionic Compounds Page Moles of Compounds Page Percent Composition Page Determining Empirical and Molecular Formulas Page The Biological Periodic Table Page 107

3-3 CHEM 100, FALL 2011, LA TECH Chapter 3. KEY CONCEPTS Chemical Compounds Molecular, condensed, and structural formulas Naming Binary Molecular Compounds Straight-chain, branched-chain constitutional alkane isomers Hydrocarbons and Alcohols Ions and Ionic Compounds Charges on monatomic ions and names and formulas of polyatomic ions Naming and formula of Ions and Ionic Compounds Properties of Ionic Compared to Molecular Compounds Electrolytes and non-electrolytes Mole of Chemical Compounds Formula of a hydrated ionic compound Percent Composition Determining Empirical and Molecular Formulas Identify biologically important elements Identify the important functional groups in Biomolecules: Carbohydrates and Fats

3-4 CHEM 100, FALL 2011, LA TECH What is a Compounds? They are made up of a collection of two or more different atoms and ions. CO 2 - carbon dioxide SO 2, - sulfur dioxide C 3 H 8 - propane FeCl 3, iron (III) chloride SnCl 2 tin (II) chliride

3-5 CHEM 100, FALL 2011, LA TECH Types of Compounds A) Molecular or Covalent Compounds A) Molecular or Covalent Compounds: non-metal + non-metal nonmetal oxide or halides: SO 2 nonmetal oxide or halides: SO 2 Organic compounds: C 3 H 8 Organic compounds: C 3 H 8 B) Ionic compounds: B) Ionic compounds: Metal + non-metal: Metal + non-metal: Type I a) Type I ionic compound (fixed charge) NaCl Type II b) Type II ionic compound FeCl 2 and FeCl 3, SnCl 2 and SnCl 4

3-6 CHEM 100, FALL 2011, LA TECH Formula of a Compound Formula are used to represent elements and compound. For molecular compounds, formula tell how many of each kind of atom are in a molecule. For ionic compounds, formula tell the simples ratio of actions and anions. Formula are used to represent elements and compound. For molecular compounds, formula tell how many of each kind of atom are in a molecule. For ionic compounds, formula tell the simples ratio of actions and anions. Molecular Weight ? Molecular compounds and Formula Weight? Ionic compounds and Formula Weight? Ionic compounds

3-7 CHEM 100, FALL 2011, LA TECH Types of Chemical Formula Molecular Shows ratio of atoms each element in the compound. E.g ethyl alcohol: C 2 H 6 O Condensed Shows groups of atoms bonded together in the formula. E.g ethyl alcohol: CH 3 CH 2 OH Structural Shows bonding of important groups in the formula E.g ethyl alcohol:

3-8 CHEM 100, FALL 2011, LA TECH Ball and Stick Models of Molecular Compounds

3-9 CHEM 100, FALL 2011, LA TECH Models of Ethanol

3-10 CHEM 100, FALL 2011, LA TECH Naming Binary Molecular-Covalent Compounds For compounds composed of two non-metallic elements, the more metallic element is listed first. To designate the multiplicity of an element, Greek prefixes are used: mono  1; di  2; tri  3; tetra  4; penta  5; hexa  6; hepta  7; octa  8

3-11 CHEM 100, FALL 2011, LA TECH Simple Binary Molecular Compounds H 2 Owater (common name) NH 3 ammonia (common name ) N 2 Odinitrogen oxide (nitrous oxide) NOnitrogen monoxide (nitric oxide) NO 2 nitrogen dioxide N 2 O 4 dinitrogen tetroxide COcarbon monoxide CS 2 carbon disulfide SO 3 sulfur trioxide CCl 4 carbon tetrachloride PCl 5 phosphorus pentachloride SF 6 sulfur hexafluoride

3-12 CHEM 100, FALL 2011, LA TECH Catenation The formation of chains of atoms of the same element. This key feature of carbon permits a vast number of compounds to exist. Four types of hydrocarbons 1) Alkanes Alkanes (saturated): single C-C bonds 2) Alkenes Alkenes (unsaturated): double C=C bond 3) Alkynes Alkynes (unsaturated): triple bond 4) Aromatic Aromatic (unsaturated): benzene rings Hydrocarbons

3-13 CHEM 100, FALL 2011, LA TECH Classifying Organic Compounds Examples Functional Group Ending Hydrocarbons C and H only -ane Alcohols OH R-OH -ol Acids COOH R-COOH -oic acid Amines NH 2 R-NH 2 -amine Ketones C=O R(C=O)R’ -one Aldehydes CHO R-CHO -al

3-14 CHEM 100, FALL 2011, LA TECH Hydrocarbons and Alcohols alkanes – C n H 2n+2 E.g. C 5 H 12 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 where R refers to the hydrocarbon radical backbone created by substituting an -OH functional group for a H atom in the hydrocarbon

3-15 CHEM 100, FALL 2011, 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 octane – C 8 H 18 nonane – C 9 H 20 nonane – C 9 H 20 decane – C 10 H 22

3-16 CHEM 100, FALL 2011, LA TECH Base names of hydrocarbons Prefix Carbons Meth-1 Eth-2 Prop-3 But-4 Pent-5 Hex-6 Hept-7 Oct-8 Non-9 Dec- 10 I see much memorization in your future!

3-17 CHEM 100, FALL 2011, LA TECH Butane Butane molecules are present in the liquid and gaseous states in the lighter

3-18 CHEM 100, FALL 2011, LA TECH As the chain length of Alkane/Alcohols increases so is the boiling point

3-19 CHEM 100, FALL 2011, LA TECH Straight & Branch-Chain Alkanes

3-20 CHEM 100, FALL 2011, LA TECH Some Common Alkyl Groups

3-21 CHEM 100, FALL 2011, LA TECH What is an Isomer? What is an Isomer? Compounds with the same number and type of atoms but with different arrangements. Molecular Formula C 5 H 12 Condensed formulas. 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.

3-22 CHEM 100, FALL 2011, LA TECH Alkane Isomers is there a formula?

3-23 CHEM 100, FALL 2011, LA TECH Naming Branch-Chain Alkanes Select the longest chain alkane as the base name Determine the side chains and give them a number corresponding to the carbon number on the base chain Use Greek prefixes of mono-(1), bi-(2), tri(3), etc. for multiplicity of same side chain

3-24 CHEM 100, FALL 2011, LA TECH Naming Branch-Chain Alkanes

3-25 CHEM 100, FALL 2011, LA TECH Alcohol example C - C - C - C - O - H Base contains 4 carbon -Parent alkane name is butane -e -ol -remove -e and add -ol alcohol name - butanol OH is on the first carbon so -1-butanol CH 3 CH 2 CH 2 CH 2 OH

3-26 CHEM 100, FALL 2011, LA TECH Ionic Compounds Characteristics of compounds with ionic bonding: Compound of metal and non-metal Composed of ions: cation and anion non-volatile, thus high melting points solids do not conduct electricity, but melts (liquid state) do many, but not all, are water soluble

3-27 CHEM 100, FALL 2011, LA TECH Ions Ions are charged particles formed by the transfer of electrons between elements or combinations of elements. Cation - a positively charged ion. Ca Ca e - Anion - a negatively charged ion. F 2 + 2e - 2F -

3-28 CHEM 100, FALL 2011, LA TECH Formation of Ionic Compound, NaCl

3-29 CHEM 100, FALL 2011, LA TECH Valance Electrons & Charge on Ions Outermost electrons (valance electrons) in an atom lost or gained metals form positive monatomic ions non-metals form negative monatomic ions Ionic compounds have electrical neutrality

3-30 CHEM 100, FALL 2011, LA TECH Valence or of Metal Ions Monatomic Ions (Type I) Group IA  +1 Group A # Group IIA  +2 Group A # Non-metals Group IIB  -1 (8 - Group B #) Monatomic Ions (Type II) Transition metal ionic compounds: have ions with different charges E.g. Iron :Fe 2+ and Fe 3+

3-31 CHEM 100, FALL 2011, LA TECH Charges on Some Common Monatomic Cations and Anions

3-32 CHEM 100, FALL 2011, LA TECH Polyatomic Ions more than one atom joined together have negative charge except for NH 4 + and its relatives negative charges range from -1 to to -4 Table in the Book

3-33 CHEM 100, FALL 2011, LA TECH Polyatomic Ions AmmoniumNH 4 + perchlorateClO 4 1- cyanideCN 1- hydroxideOH 1- nitrateNO 3 1- sulfateSO 4 2- carbonateCO 3 2- phosphatePO 4 3-

3-34 CHEM 100, FALL 2011, LA TECH Names of Ionic Compounds 1. Name the metal first. If the metal has more than one oxidation state, the oxidation state is specified by Roman numerals in parentheses. If the metal has more than one oxidation state, the oxidation state is specified by Roman numerals in parentheses. 2. Then name the non-metal, changing the ending of the non-metal to changing the ending of the non-metal to -ide.

3-35 CHEM 100, FALL 2011, LA TECH Metals with multiple charges Transition metals. Here it is easier to list the ones that to only have a single common oxidation state. All Group 3B- 3+ Ni, Zn, Cd- 2+ Ag- 1+ Lanthanides and actinides - 3+ (common)

3-36 CHEM 100, FALL 2011, LA TECH Ionic compounds Na + Mg 2+ Al 3+ Cl - O 2- N 3- Some simple ions Formula for some ionic compounds NaClMgCl 2 AlCl 3 Na 2 O MgO Al 2 O 3 Na 3 N Mg 3 N 2 AlN Cations Anions Exchange charge as subscripts on the metal and nonmetal Give the simple ratio

3-37 CHEM 100, FALL 2011, LA TECH Nomenclature NaCl Fe 2 O 3 NH 4 NO 3 KClO 4 CaCO 3 NaOH AgNO 3 Mg(C 2 H 3 O 2 ) 2 Co 2 (SO 4 ) 3 KI Mg 3 N 2 NaClsodium chloride Fe 2 O 3 iron(III) oxide NH 4 NO 3 ammonium nitrate KClO 4 potassium perchlorate CaCO 3 calcium carbonate NaOH sodium hydroxide AgNO 3 silver nitrate Mg(C 2 H 3 O 2 ) 2 magnesium acetate Co 2 (SO 4 ) 3 cobalt(III) sulfate KI potassium iodide Mg 3 N 2 magnesium nitride

3-38 CHEM 100, FALL 2011, LA TECH Ionic Crystal Lattice NaCl “table salt”

3-39 CHEM 100, FALL 2011, LA TECH Cleaving NaCl

3-40 CHEM 100, FALL 2011, LA TECH

3-41 CHEM 100, FALL 2011, LA TECH Electrical Conductivity of Ionic Solution Electrolytes Aqueous solutions conducts electricity strong-electrolytes weak-electrolytes Non-electrolytes Aqueous solutions do not conducts electricity

3-42 CHEM 100, FALL 2011, LA TECH

3-43 CHEM 100, FALL 2011, LA TECH Naming Acids formula starts with H HCl HCl HNO 3 HNO 3 H 2 SO 4 H 2 SO 4 HClO 3 HClO 3 H 3 BO 3 H 3 BO 3 H 3 PO 4 H 3 PO 4 Hydrochloric acid Nitric acid Sulfuric acid Chloric acid Boric acid Phosphoric acid

3-44 CHEM 100, FALL 2011, LA TECH HClO hypochlorous ClO¯ ”hypochlorite HClO 2 chlorous ClO 2 ¯ chlorite HClO 3 chloric ClO 3 ¯ chlorate HClO 4 perchloric ClO 4 ¯ perchlorate HNO 3 nitric NO 3 ¯ nitrate HNO 2 nitrous NO 2 ¯ nitrite Names of acids and ions

3-45 CHEM 100, FALL 2011, LA TECH Naming bases formula ends with OH NaOH sodium hydroxide NaOH sodium hydroxide Ba(OH) 2 barium hydroxide Ba(OH) 2 barium hydroxide KOH potassium hydroxide KOH potassium hydroxide NH 4 OH ammonium hydroxide NH 4 OH ammonium hydroxide Ca (OH) 2 calcium hydroxide Ca (OH) 2 calcium hydroxide

3-46 CHEM 100, FALL 2011, LA TECH Percentage Composition description of a compound based on the percent relative amounts of each element in the compound

3-47 CHEM 100, FALL 2011, LA TECH % Element Composition in Compounds from Formula n x Gram Atomic weight % mass = x 100 formula weight (GMW, GFW) n= subscript of the element in the formula

3-48 CHEM 100, FALL 2011, LA TECH Example: What is the percent composition of carbon in chloroform, CHCl 3, a substance once used as an anesthetic? MM = 1(gaw) C + 1(gaw) H + 3(gaw) Cl = (  )amu = amu 1(12.011) 1(12.011) %C =  100 = % C ( ) 1( ) %H =  100 = % H (35.453) 3(35.453) %Cl =  100 = % Cl

3-49 CHEM 100, FALL 2011, LA TECH Example: What is the percent composition of chloroform, CHCl 3, a substance once used as an anesthetic? %C = % C %H = 0.844% H %Cl = % Cl %Cl = % Cl

3-50 CHEM 100, FALL 2011, LA TECH 6 x 12 %C= x 100 = 40.00% C x 1.01 % H= x 100 = 6.73% H x %O= x 100 = 53.29% O % Mass percent of element in C 6 H 12 O 6 Molar Mass = g/mol

3-51 CHEM 100, FALL 2011, LA TECH What is Empirical Formula? Simple whole number ratio of each atom expressed in the subscript of the formula. Molecular Formula = C 6 H 12 O 6 C 6 H 12 O 6 of glucose Empirical Formula = CH 2 O Empirical formula is calculated from % composition

3-52 CHEM 100, FALL 2011, LA TECH How do you get Empirical Formula from % composition and vice versa?

3-53 CHEM 100, FALL 2011, LA TECH Example: The burning of fossil fuels in air produces a brown-colored gas, a major air pollutant, that contains 2.34 g of N and 5.34 g of O. What is the empirical formula of the compound? 5.34 %O =  100 = 69.5% O %N =  100 = 30.5% N

3-54 CHEM 100, FALL 2011, LA TECH %N = 30.5% N%O = 69.5% O Relative # Atoms Relative # AtomsMultiply % (%/gaw) Divide by Smallerby Integer % (%/gaw) Divide by Smallerby Integer N / = /2.18 =  1.00  1 O / = /2.18 =  1.99  2 Empirical Formula  NO 2 Empirical Formula Weight = 46.0 Empirical Formula from % composition

3-55 CHEM 100, FALL 2011, LA TECH Molecular formula from Empirical formula Molecular Formula = n x empirical Formula Molecular weight 180

3-56 CHEM 100, FALL 2011, LA TECH Molecular Formula from Empirical Empirical Formula Weight 30 Empirical Formula Weight 30 Molecular Formula = (CH 2 O) n = (CH 2 O) 6 Molecular Formula = C 6 H 12 O 6 of glucose Molecular Formula Weight = 180 Molecular Formula Weight 180 n = = = 6 Empirical Formula Weight 30

3-57 CHEM 100, FALL 2011, LA TECH Example: A colorless liquid used in rocket engines, whose empirical formula is NO 2, has a molar mass (MW) of What is the molecular formula? FM = 1(gaw) N + 2(gaw) O = 46.0 MM 92.0 MM 92.0 X = = = 2 FM 46.0 FM 46.0 thus MF = 2  EF thus MF = 2  EF N 2 O 4

3-58 CHEM 100, FALL 2011, LA TECH Combustion Analysis

3-59 CHEM 100, FALL 2011, LA TECH Example Benzoic acid is known to contain only C, H, and O. A 6.49-mg sample of benzoic acid was burned completely in a C-H analyzer. The increase in the mass of each absorption tube showed that 16.4-mg of CO 2 and 2.85-mg of H 2 O formed. What is the empirical formula of benzoic acid? 4.48-mg C %C =  100 = 68.9% C 6.49-mg sample (16.4-mg of CO2 )(12.01-mg C) #mg C = = 4.48-mg C (44.01-mg CO2 )

3-60 CHEM 100, FALL 2011, LA TECH Example Benzoic acid is known to contain only C, H, and O. A 6.49-mg sample of benzoic acid was burned completely in a C-H analyzer. The increase in the mass of each absorption tube showed that 16.4-mg of CO 2 and 2.85-mg of H 2 O formed. What is the empirical formula of benzoic acid? mg H %C =  100 = 4.92% H 6.49-mg sample (2.85-mg of H2O )(2.02-mg H) #mg H = = mg H (18.02-mg H2O)

3-61 CHEM 100, FALL 2011, LA TECH Example Benzoic acid is known to contain only C, H, and O. A 6.49-mg sample of benzoic acid was burned completely in a C-H analyzer. The increase in the mass of each absorption tube showed that 16.4-mg of CO 2 and 2.85-mg of H 2 O formed. What is the empirical formula of benzoic acid? 68.9% C 4.92% H % O = (100 - (68.9% C % H) = 26.2% O

3-62 CHEM 100, FALL 2011, LA TECH Example Benzoic acid is known to contain only C, H, and O. A 6.49-mg sample of benzoic acid was burned completely in a C-H analyzer. The increase in the mass of each absorption tube showed that 16.4-mg of CO 2 and 2.85-mg of H 2 O formed. What is the empirical formula of benzoic acid? % C 68.9 H 4.92 O 26.2 (%/gaw) 68.9/12.0 = /1.01 = /16.0 = 1.64 Divide by Smallest 5.75/1.64 = /1.64 = /1.64 = 1.00 Multiply by Integer 3.51  2 =  2 =  2 = 2 Relative # Atoms C7H6O2C7H6O2

3-63 CHEM 100, FALL 2011, LA TECH Biological Periodic Table

3-64 CHEM 100, FALL 2011, LA TECH

3-65 CHEM 100, FALL 2011, LA TECH Important Functional Groups A functional group is a group of atoms consisting of O, H, C, N, P and S attached to a carbon skeleton of an alkane that affect its properties and reactivity.

3-66 CHEM 100, FALL 2011, LA TECH Classifying Organic Compounds HydrocarbonsC and H only Alcohols OH R-OH Acids COOH R-COOH Amines NH 2 R-NH 2 Ketones C=O R(C=O)R’ Aldehydes CHO R-CHO

3-67 CHEM 100, FALL 2011, LA TECH Carbohydrates Carbohydrates are sugars and long polymers of sugars, such as starches and cellulose. Monosaccharides are single sugar units and are also called “simple sugars”. Disaccharides consist of two sugar units linked together. Polysaccharides are long polymers made of individual sugar units, usually of the monomer glucose.

3-68 CHEM 100, FALL 2011, LA TECH Glucose

3-69 CHEM 100, FALL 2011, LA TECH Sucrose

3-70 CHEM 100, FALL 2011, LA TECH Fats Fats are large molecules made from two types of building blocks, Glycerol (a polyalchohol) Glycerol (a polyalchohol) Fatty acids (long hydrocarbon chains of C with a single carboxylic acid group at one end). Fatty acids (long hydrocarbon chains of C with a single carboxylic acid group at one end). Fats are not polymers. Structure of a fat, also known as a triacylglycerol

3-71 CHEM 100, FALL 2011, LA TECH Tristearin - Glycerol - Stearic Acid

3-72 CHEM 100, FALL 2011, LA TECH Saturated/Unsaturated fatty acids Unsaturated fatty acids contain C=C double bonds may take one or two forms at a double bond. In the cis form the chain bends at an angle of about 30 degree, producing a kink.