SAT II CHEM PREP PPT

SAT II CHEM PREP PPT Mrs Gupta Modified from Mark Rosengarten’s Powerpoint Setup of the SAT II Chem Exam • • • • 85 total questions, hour (about 42 s/question) - All multiple choice, 1/4th point taken off for every incorrect answer - if you can narrow down to two choices, then guess otherwise leave blank - scoring scale from 200-800 What to Bring to the Exam • • • #2 pencil, eraser No calculators allowed (brush up on your basic math skills) Your brain Please don’t leave it at home.:) How To Prepare • DO NOT CRAM Get your studying done with by the night before Get a good night’s • Actively participate in any and all review classes and activities offered by your sleep and have breakfast the morning of the exam teacher Matter 1) Properties of Phases 2) Types of Matter 3) Phase Changes Properties of Phases • • • Solids: Crystal lattice (regular geometric pattern), vibration motion only Liquids: particles flow past each other but are still attracted to each other Gases: particles are small and far apart, they travel in a straight line until they hit something, they bounce off without losing any energy, they are so far apart from each other that they have effectively no attractive forces and their speed is directly proportional to the Kelvin temperature (Kinetic-Molecular Theory, Ideal Gas Theory) Solids The positive and negative ions alternate in the ionic crystal lattice of NaCl Liquids When heated, the ions move faster and eventually separate from each other to form a liquid The ions are loosely held together by the oppositely charged ions, but the ions are moving too fast for the crystal lattice to stay together Gases Since all gas molecules spread out the same way, equal volumes of gas under equal conditions of temperature and pressure will contain equal numbers of molecules of gas 22.4 L of any gas at STP (1.00 atm and 273K) will contain one mole (6.02 X 1023) gas molecules Since there is space between gas molecules, gases are affected by changes in pressure Types of Matter • Substances (Homogeneous) – Elements (cannot be decomposed by chemical change): Al, Ne, O, Br, H – Compounds (can be decomposed by chemical change): NaCl, Cu(ClO3)2, KBr, H2O, C2H6 • Mixtures – Homogeneous: Solutions (solvent + solute) – Heterogeneous: soil, Italian dressing, etc Ester Esters are named for the alcohol and organic acid that reacted by esterification to form the ester If the alcohol was 1-propanol and the acid was hexanoic acid, the name of the ester would be propyl hexanoate Esters contain a COO (carboxyl) group in the middle of the molecule, which differentiates them from organic acids Amine - Component of amino acids, and therefore proteins, RNA and DNA…life itself! - Essentially ammonia (NH3) with the hydrogens replaced by one or more hydrocarbon chains, hence the name “amine”! Amide Synthetic Polyamides: nylon, kevlar Natural Polyamide: silk! For more information on polymers, go here Organic Reactions • • • • • Combustion Fermentation Substitution Addition Dehydration Synthesis – – • • Etherification Esterification Saponification Polymerization Combustion • Happens when an organic molecule reacts with oxygen gas to form carbon dioxide and water vapor Also known as “burning” Substitution • • Alkane + Halogen → Alkyl Halide + Hydrogen Halide The halogen atoms substitute for any of the hydrogen atoms in the alkane This happens one atom at a time The halide generally replaces an H on the end of the molecule C H + Cl  C H Cl + HCl 2 The second Cl can then substitute for another H: C H Cl + HCl  C H Cl + H 2 Addition • • Alkene + Halogen → Alkyl Halide The double bond is broken, and the halogen adds at either side of where the double bond was One isomer possible (c) 2006, Mark Rosengarten Etherification* • • Alcohol + Alcohol → Ether + Water A dehydrating agent (H SO ) removes H from one alcohol’s OH and removes the OH from the other The two molecules join where there H and OH were removed Note: dimethyl ether and diethyl ether are also produced from this reaction, but can be separated out Esterification • • Organic Acid + Alcohol → Ester + Water A dehydrating agent (H SO ) removes H from the organic acid and removes the OH from the alcohol The two molecules join where there H and OH were removed Saponification The process of making soap from glycerol esters (fats) Glycerol ester + NaOH  soap + glycerol Glyceryl stearate + NaOH  sodium stearate + glycerol The sodium stearate is the soap! It emulsifies grease…surrounds globules with its nonpolar ends, creating micelles with - charge that water can then wash away Hard water replaces Na+ with Ca+2 and/or other low solubility ions, which forms a precipitate called “soap scum” Water softeners remove these hardening ions from your tap water, allowing the soap to dissolve normally Polymerization • A polymer is a very long-chain molecule made up of many monomers (unit molecules) • The polymer is named for the monomer that made it joined together – – • • • Polystyrene is made of styrene monomer Polybutadiene is made of butadiene monomer Addition Polymers Condensation Polymers Rubber Addition Polymers Joining monomers together by breaking double bonds Polyvinyl chloride (PVC): vinyl siding, PVC pipes, etc Vinyl chloride n C2H3Cl polyvinyl chloride  -(-C2H3Cl-)-n Polytetrafluoroethene (PTFE, teflon): TFE n C2 F PTFE  -(-C2F4-)-n Condensation Polymers Condensation polymerization is just dehydration synthesis, except instead of making one molecule of ether or ester, you make a monster molecule of polyether or polyester Rubber The process of toughing rubber by cross-linking the polymer strands with sulfur is called THE END (c) 2006, Mark Rosengarten ...Setup of the SAT II Chem Exam • • • • 85 total questions, hour (about 42 s/question) - All multiple choice, 1/4th... Substances (Homogeneous) – Elements (cannot be decomposed by chemical change): Al, Ne, O, Br, H – Compounds (can be decomposed by chemical change): NaCl, Cu(ClO3)2, KBr, H2O, C2H6 • Mixtures... allowed (brush up on your basic math skills) Your brain Please don’t leave it at home.:) How To Prepare • DO NOT CRAM Get your studying done with by the night before Get a good night’s • Actively