高考化学个考点精讲 考点 化学反应中的能量变化（College entrance examination chemistry test sites, precise test site chemical reaction in the energy change）

《高考化学个考点精讲 考点 化学反应中的能量变化（College entrance examination chemistry test sites, precise test site chemical reaction in the energy change）》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。

1、高考化学58个考点精讲考点3化学反应中的能量变化（Collegeentranceexaminationchemistry58testsites,precisetestsite3chemicalreactionintheenergychange）Testsite3energychangeinchemicalreactions1.reviewthekeypointsUnderstandthechangeinenergyinachemicalreactionUnderstandingexothermicreac

2、tions,endothermicreactionsUnderstandthereactionheat,combustionheatandheat,andtheheatequationofwriting2.difficultiesfocusI.heatofreaction1.Theamountofheatreleasedorabsorbedduringachemicalreaction,usuallycalledreactionheat.Thereactionheatisindicatedbythesym

3、bolDeltaH,andtheunitisusuallykJ/mol.WhenHisnegative,itisexothermic;whenHispositive,itisendothermicreaction.Aninstrumentformeasuringtheheatofreactioniscalledacalorimeter.2.Combustionheat:at101kPa,whenthesubstance1moliscompletelyburned,theheatreleasedfromth

4、estableoxideiscalledtheburningheatofthesubstance.3,neutralizationheat:indilutesolution,theacidandalkalineutralizationreactiontoproduce1molH2O,atthistimethereactionheatcalledneutralizationheat.Themiddleschoolstagemainlydealswiththereactionsofstrongacidsand

5、strongbases.Twothermochemicalequation1,thewritingheatresponseequationshouldpayattentiontotheproblem:(1)becausethevalueofthereactionheatisrelatedtothetemperatureandpressureofthereaction,itmustbenotedthat"101kPa"and"25"arenotindicated.(2)theaggregationstate

6、ofmatterisdifferent,thenumericalvalueofreactionheatisdifferent,sotheaggregationstateofmattershouldbeindicated.(3)thestoichiometricquantityinathermochemicalequationisthequantityofasubstanceofthecorrespondingsubstance.Itcanbeeitheranintegerorafraction.2,wri

7、tethegeneralstepsofthermochemicalequations(1)writethechemicalequationindicatingtheaggregatedstateaccordingtorelevantinformationandtrim.(2)accordingtothestoichiometricnumberofeachsubstanceinthechemicalequation,thecorrespondingnumericalvalueofthereactionhea

8、tiscalculated.(3)iftheexothermicreactionisnegative,thedeltaHisnegative,andiftheendothermicreactionispositive,thedeltaHispositive.Andwriteinthefirststepoftheequationbehind,inthemiddlewith".".(4)ifthesubjectotherwiser