Transcript Lecture 3
Outline 1/15/07 Announcements Turn in seminar reports - to me CAPA set#1 - due tonight Discussion section – Mon @ 4pm Summer Research – Wed @ 6:30pm Review Chapter 12 calculations Review biofilms & Start Chapter 13 Questions: DISCUS logins? CAPA due tonight? – problem #9 Practice calculations of Colligative Property effects Freezing Point Depression Kf = -1.858°C/m DT = Kf m Boiling Point Elevation Kb = 0.512°C/m DT = Kb m where Kf and Kb are constants and m is concentration of solute in terms of molality (mols/kg solvent) Worksheet #1 problems: 100 kg NaF is added to 10000 L of H2O Freezing Point Depression: DT = Kf m Kf = -1.858 C kg/mol (for water) 100000g NaF 42 g/mol = 2381 mol NaF 2381 mol NaF 2 ions = 4762 mols solute 10000 L H2O = 10000 kg solvent Freezing Point Depression: DT = -1.858 0.4762 = -0.884°C Worksheet #1 problems: 2.00 g sucrose is added to 500 mL of H2O Osmotic Pressure: p = mRT R = .08206 L-atm/mol K 2.00g 342 g/mol = .00585 mol sucrose 0.500 L H2O = 0.5 kg solvent Osmotic Pressure: p = 0.117 0.08206 300 = .288 atm = 219 torr p.108 Like dissolves like…. What is a macromolecule? biopolymers Organic Chemistry: Nomenclature: Alkanes, Alkenes, Alkynes Branched chain alkanes Aromatic compounds Functional groups Organic Reactions Polymers Definitions Properties Intro to Biochemistry…. Organic Chemistry: Nomenclature: Alkanes, Alkenes, Alkynes Branched chain alkanes Aromatic compounds Functional groups Organic Reactions Polymers All are just definitions…. need to know the language…. Alkanes methane ethane propane butane pentane hexane heptane octane nonane etc., Identify the alkane: butane Organic Nomenclature: Root refers to the # of carbon atoms: Methane Ethane Ethene Ethyne Propane Propene Propyne Butane Butene Butyne Pentane … … Hexane Septane Octane Alkanes Alkenes Alkynes single bonds double bonds triple bonds Alkenes ethene propene # refers to position... 1-butene, 2-butene 1-pentene, 2-pentene, 3-pentene 1-butene cis-2-butene trans-2-butene Alkanes, All single bonds Alkenes, Alkynes A double bond A triple bond somewhere somewhere What if the C atoms are not in a row? 2-methyl-butane “Branched-chain alkanes” alkane methane ethane propane butane pentane hexane heptane octane nonane alkyl- prefix methylethylpropylbutylpentylhexylheptyloctylnonyl Practice: Draw a structure of 3-ethyl-heptane 1 2 3 Aromatic compounds: (Rings) B benzene T toluene gasoline E ethylbenzene X xylene napthalene mothballs What do all aromatic compounds share? Aromatic compounds: (Rings) Delocalized e.g. 1,3,5 trinitro toluene (TNT) electrons!!! (& smell) Organic nomenclature (cont’d) Organic Functional Groups: Alcohols: -OH e.g. 2-propanol Acids: -C=OOH Section 13.1 Ketones: -C=O Esters: -C=OOEthers: -OAldehydes: -C=OH Amines: -NH2 etc. Polymerizable Functional Groups p. 111 Polymer Linkage Groups p. 111 Functional Groups Carbon combines with other atoms (mainly H, N, O, S and halogens) to form “functional groups” Sites of typical reactions Used to classify organic compounds Serve as a basis for naming compounds