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1、高中化学58个精讲(27)化学反应速率(58lecturesinSeniorMiddleSchoolChemistry(27)chemicalreactionrate)Highschoolchemistry58testsites27,therateofchemicalreaction1.reviewthekeypoints1.understandtheconceptandexpressionmethodofchemicalreactionrate2.understandtheeffectsofconcentration,temper
2、ature,pressure,andcatalystconditionsontherateofchemicalreaction3.,theeffectsofconcentration,pressure,temperatureandcatalystontherateofchemicalreactionareexplainedbytheeffectivecollision,theorientationofthecollisionandtheactivationmolecules2.difficultiesfocus(I)rateofch
3、emicalreaction:ThespeedofthedifferentchemicalreactionsisdifferentSomegoveryfast...Inaflash,suchashydrogenandoxygenmixtureexplosion,acidandalkalineutralization,etc.Somecarryonslowly;ittakeshours;afewdays;evenhundredsofyears;millionsofyears...Forexample,thereactionbetwee
4、norganiccompoundsisgenerallyslowandtakeshoursorevendays;thedecompositionofplasticstakeshundredsofyears......Rateofchemicalreaction:Areductionintheconcentrationofreactants(oranincreaseintheconcentrationofanagent)perunittime,indicatingtherateatwhichachemicalreactiontakes
5、placeAunitofconcentrationcommonlyused:mol/L.Aunitofchemicalreactionrate:mol/(L;min)mol/(L=s)Example:nitrogenandhydrogenarecontainedinaclosedvessel.Atthebeginningofthereaction,theconcentrationofnitrogenis2mol/L,andtheconcentrationofhydrogenis5mol/L.After2minutes,theconc
6、entrationofnitrogenwas1.6mol/L,andtherateofchemicalreactioninthesetwominuteswascalculated.Thechemicalreactionrateisindicatedbythechangeofnitrogenconcentration.Whatifhydrogenisusedandammoniaisused?Obviously,therateofthesamechemicalreactionisexpressedbythechangeoftheconc
7、entrationofdifferentsubstancesTherefore,whentherateofchemicalreactionisindicated,thesubstancemustbeindicatedTheratiooftherateofthesamechemicalreactionrepresentedbydifferentsubstancesisequaltotheratioofstoichiometricquantities(two)theinfluenceofexternalconditionsonthera
8、teofchemicalreaction:Differentchemicalreactionshavedifferentreactionrates(e.g.,explosionofhydrogenandoxygenmixture;ne