Properties of Water Water Properties Solid Liquid Gas Solid water floats on liquid water High surface tension Universal solvent High specific heat High heat of vaporization http www unit5 org christjs Matter 20and 20Energy Unit 202 20PP files frame htm In liquid phase the water molecules fit closely together Polar nature allows them to attract one another Most dense at 4 C Water Molecule Bent molecule C Covalent l tb bonds d Polar Dissolves ionic substances Liquid water molecules H2O l Water http www chemlin net news 2007 mar2007 water htm High Surface Tension Liquid Water http www unit5 org christjs Matter 20and 20Energy Unit 202 20PP files frame htm Dissolution of ionic substance Water Molecule http www webelements com nexus node 786 http quest nasa gov space teachers microgravity 6surf html Bent Polar P l 1 Molecular Structure of Ice Solid Ice Water Expansion Molecule shape fit together closer in liquid Open structured crystal due to hydrogen bonding of polar molecules upon freezing H2O s Ice Zumdahl Zumdahl DeCoste World of Chemistry 2002 page 455 http www unit5 org christjs Matter 20and 20Energy Unit 202 20PP files frame htm http www unit5 org christjs Matter 20and 20Energy Unit 202 20PP files frame htm Crystal structure of ice Three phases of water In solid phase of water arrangement becomes more open less dense Ice floats because of this Expansion of 9 upon freezing Three Phases of Water at Earth s Surface Liquid Solid Vapor Energy captured or released upon change from one phase to another http www its caltech edu atomic snowcrystals primer primer htm http www cdli ca CITE glaciers htm Gas Steam Gas Solid and Liquid Water phases and molecules H2O g Steam Zumdahl Zumdahl DeCoste World of Chemistry 2002 page 441 http www unit5 org christjs Matter 20and 20Energy Unit 202 20PP files frame htm http www unit5 org christjs Matter 20and 20Energy Unit 202 20PP files frame htm 2 Evaporation Water vapor Evaporation or Not http www geology sdsu edu classes geol351 01watercycle watercyclefigs htm Kinetic energy of molecules great enough to escape surface Energy is taken from liquid cools it Gaseous G phase h or vapor phase h Air inside glass become saturated with water and no more water can evaporate from the surface Outside glass is open system that is not saturated http en wikipedia org wiki Water vapor Boiling http www chem purdue edu gchelp liquids boil2 html Boiling Temperature Boiling http www deepseaimages com dsilibrary showphoto php photo 2912 password sort 1 size medium cat 853 page 1 Boiling Temp vs Pressure Microscopic boiling http www chem purdue edu gchelp liquids boil2 html Pressure Cooker For any given pressure there is a temperature at which water boils The temperature of the water remains at that temperature until all of the water has been changed from liquid to vapor The length of time for this to occur does not have an effect on this temperature http www chem purdue edu gchelp liquids boil2 html http www goodmans net get item ma 6qt maitres 806212 6 qt cooker htm 3 Pressure canner Boiling at less than 100 o C Pour in hot water Reduce Pressure with syringe Condensation Opposite of evaporation Kinetic energy of molecules running into surface of liquid and joining it Heats H t environment i t http www micrecol de air2 html http hgic clemson edu factsheets HGIC3020 htm Condensation on Glass Atmosphere Evaporation Energy goes into air Cools remaining water Condensation C d ti Energy goes from air to surface Warms local environment Atmosphere Warm air has greater capacity for holding water in the vapor phase Saturation at capacity Relative R l ti H Humidity percent idit t off water t contained compared to saturated amount at that temperature http www geology sdsu edu classes geol351 01watercycle watercyclefigs htm Water Vapor Capacity http www wdtv com weather images Weather Review humidity htm Condensation http observe arc nasa gov nasa earth hydrocycle graphics condensation jpg Condensation diagram http weatherstreet com weatherquestions What is condensation htm 4 Sea Fog Coastal fog Energy of Water Phase Change Calorie energy to change 1 g water 1 K or 1 oC Also need energy to change to different state of matter Energy of vaporization condensation 540 calories per gram of water 2256 J g Energy of melting freezing 80 calories per gram 334 J g http www anythingmarine co uk anything met htm Temperature Measure of hotness Celsius 0o freezing point of pure water at standard pressure 100o boiling point at standard pressure Fahrenheit 0o was lowest attained 32 was his age when he performed experiments 212 is boiling point in those increments http www victoriaweather ca clouds php image fog Temperature Convert with equations Order of operations Parentheses first Then multiply or divide Add or subtract last Or use adjacent scales such as p 142 of Conceptual Physical Science textbook 5 C F 32 9 9 F C 32 5 Temperature Kelvin same size as degree Celsius Absolute Zero is 0 K notice no degree symbol on K 0o C 273 K Molecular motion ceases at absolute zero 5
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