WATER PROPERTIESBe sure to attend lab this weekCovalent BondsCovalent Bond—Chlorine GasOctet Rule for OxygenNaming CompoundsPolar moleculesElectro-negativityPoly-atomic ionsCommon poly-atomic ionsChemical FormulasChemical FormulasPredict Molecule ShapeElectro-negativityPredict Molecule ShapePredict Molecule ShapeGeometry of MoleculesTypical Shapes of MoleculesTetrahedral moleculesPyramidal moleculesBent moleculesPolar moleculesDipole attraction in solid and liquidDissolution of ionic substanceSolute/SolventWater phases and moleculesWater MoleculeProperties of WaterDistribution/Cycle AnimationHydrologic CycleNatural substances in waterImpurities in RunoffOrganic byproducts in waterContamination of WaterDrinking water standardsBe sure to attend lab this weekHeat and Energy TransferWater DropImpurities in RunoffOrganic byproducts in waterPollution SourcesContamination of WaterRaw Sewage dischargePlant nutrient pollutionAgricultural RunoffOil pollutionMine leachateWater PollutionWater Pollution PreventionDrinking water standardsTemperatureTemperatureTemperatureHeatSpecific Heat CapacityHeat ExpansionWater ExpansionWater MoleculeWater ExpansionWater ExpansionHeat of WaterElectron Structure DiagramsDot DiagramsPhases of MatterEvaporationWater vaporEvaporation or NotCondensationCondensation on GlassAtmosphereAtmosphereWater Vapor CapacityCondensationCondensation diagramSea FogBoilingBoilingMicroscopic boilingPressure CookerPressure cannerBoiling Temp vs.Pressure Boiling at less than 100 o CEnergy of Water Phase ChangeSolid IceIn-Class ActivityIn-Class ActivityIn-Class ActivityIn-Class ActivityIn-Class Activity1WATER PROPERTIESSupplemental Textbook MaterialCh. 16, p. 349-361Be sure to attend lab this week• Bring the lab manual• Must pass lab to pass this class• Instructors will give percent lab grade to one anotherCovalent Bonds• Need ‘octet’ of electrons surrounding element in the ‘dot diagram’• Some bonds are multiple, stronger!Covalent Bond—Chlorine Gas• Covalent bond• Draw dot diagram for each atom• Bond using all electrons• Octet around each• Show bonding pair with a lineOctet Rule for Oxygen• Start with dot diagram• Don’t have octets of electrons• Share two pairs to get to eight for each atom• Indicate with double barNaming Compounds• Find subscripts to indicate how many of each atom in the molecule• Use chart at right for number of each2Polar molecules Electro-negativityPoly-atomic ions• Covalently bonded compounds• Not electrically neutral• Maintain covalent bonds within ions as they interact with other ions to form ionic compounds• Those bonded to oxygen become ‘–ate’Common poly-atomic ions• Hydroxide OH-• Bicarbonate HCO3-• Carbonate CO32-• Sulfate SO42-• Nitrate NO3-• Phosphate PO43-• Chromate CrO42-Chemical FormulasMolecule has specific ratio of elements• Subscripts—how many• Parentheses—how many sets• Coefficients—how many molecules in reactionChemical Formulas•H2SO4•Ca3(PO4)2•Na2O + CaCl2→ CaO + 2 NaCl•MgBr2 + 2Ag(NO3) → Mg(NO3)2 + 2AgBr3Predict Molecule Shape• Draw molecule dot diagram• Put most electronegative element in the center of moleculeElectro-negativityPredict Molecule Shape• Draw molecule dot diagram• Put most electronegative element in the center of molecule• Arrange other atoms around it• Include all unbonded pairs and bonds, so that each atom has ‘octet’ of electrons• Choose tentative shape from number of atoms plus unbonded pairsPredict Molecule Shape• Choose tentative shape from number of atoms plus unbonded pairs• Erase unbonded pairs• Adjust shape to account for the empty spots– Tetrahedrons may become pyramids– 3-d shapes may become bentGeometry of Molecules Typical Shapes of Molecules4Tetrahedral moleculesPyramidal moleculesBent moleculesPolar moleculesDipole attraction in solid and liquidDissolution of ionic substance5Solute/SolventWater phases and moleculesWater Molecule• Bent • Covalent bonds• Polar• Dissolves ionic substancesProperties of Water• Solid water floats on liquid water• High specific heat• High heat of vaporization• ‘Universal’ solventDistribution/Cycle Animation Hydrologic Cycle6Natural substances in water Impurities in Runoff• Atmosphere• Dissolved substances• Silt, etc.• RadonOrganic byproducts in water Contamination of Water• Micro-organisms• Decay products• Plant nutrients• Petroleum compounds• Acid• Industry• Mining Drinking water standardsBe sure to attend lab this week• Bring the lab manual• Must pass lab to pass this class• Instructors will give percent lab grade to one another7Heat and Energy TransferSupplementary Textbook MaterialChapter 18: p. 410-420Review Questions: 2-4, 21-26Water Drophttp://www.wested.org/pblnet/exp_projects/H2O.htmlImpurities in Runoff• Atmosphere• Dissolved substances• Silt, etc.• RadonOrganic byproducts in waterPollution Sources Contamination of Water• Micro-organisms• Decay products• Plant nutrients• Petroleum compounds• Acid• Industry• Mining8Raw Sewage dischargehttp://www.nwri.ca/sande/nov_dec_2002-e.htmlPlant nutrient pollutionhttp://www.na.fs.fed.us/SPFO/pubs/n_resource/riparianforests/Tab%20I.htmAgricultural Runoffhttp://www.na.fs.fed.us/SPFO/pubs/n_resource/riparianforests/Tab%20I.htmOil pollutionhttp://www.intertanko.com/tankerfacts/sizes/pollution.htmMine leachatehttp://www.ew.govt.nz/enviroinfo/hscs/contam/Water Pollutionhttp://www.jvkco.com/digidare/water.html9Water Pollution Preventionhttp://www.jvkco.com/digidare/water.htmlDrinking water standardsTemperature• Quantity of hotness• Celsius¾0ofreezing point of pure water at standard pressure¾100oboiling point at standard pressure• Fahrenheit¾0owas lowest attained¾32 was his age when he performed experiments¾212 is boiling point in those increments Temperature• Convert with equations¾ Order of operations Parentheses first Then multiply or divide Add or subtract last• Or use adjacent scales such as in the appendix of Earth Science textbook (p. 683)32)-(F95C =32 C59F +=Temperature• Kelvin same size as degree Celsius• ‘Absolute Zero’ is 0 K¾(notice no degree symbol on K)•0oC = 273 K• Equation for Prelab exercise 2 has errorK – 273 = Co(change + to - )Heat• Calorie– Amount of heat required to raise the temperature of 1 mL pure water 1oC– Food ‘Calories’ are kilocalories• Joule ~ ¼ of calorie– 1 cal.
View Full Document
Unlocking...