review of chemistry1_第1頁
已閱讀1頁，還剩6頁未讀， 繼續(xù)免費閱讀

下載本文檔

版權(quán)說明：本文檔由用戶提供并上傳，收益歸屬內(nèi)容提供方，若內(nèi)容存在侵權(quán)，請進行舉報或認領(lǐng)

文檔簡介

1、ReviewofChemistryDerivedQuantitiesDefinitions:ADERIVEDQUANTITYisanumbermadebycombiningtwomeothervalues.ADERIVEDUNITisaunitwhichismadebycombiningtwomeotherunits.II.4DensityDefinition:Mass=thequantityofmatteronanobjectDens

2、ity=themasscontainedinagivenvolumeofasubstanceII.5SignificantfiguresexperimentaluncertaintySIGNIFICANTFIGURESA.Asignificantfigureisameasuredmeaningfuldigit.B.Anaccuratemeasurementisameasurementthatisclosetothecrectaccept

3、edvalueaprecisemeasurementisareproduciblemeasure.C.Thenumberifsignificantfiguresisequaltoallthecertaindigitsplusthefirstuncertaindigit.D.“Defined”numbers“counting”numbersareassumedtobeperfectedsothattheyare“exempt”fromth

4、erulesapplyingtosignificantfigures.BEVERUCAREFUWHENAVLAUEAPPEARSTOCOINCIDEEXACTLYWITHAMARKINGONAMEASURINGDEVICE.Thefollowingprocedureshouldhelpwhensuchasituationoccurs.THEPROCEDUREFCRECTLYREADINGMEASURINGSCALESWHENAPOINT

5、ERISEXACTLYONANUMBEREDDIVISION?Determinethevaluethatthemeasurementseemstohave.?Pretendyouhaveavalueinbetweentwooftheunnumberedsubdivisionsonyourmeasuringdevice.?Determinehowmanydecimalplacesyoucouldreadoffthemeasuringdev

6、iceatthe“inbetweenvalue”.?Addasufficientnumberofzeroestotheactualreadingtogiveyouthecrectnumberofdecimalplacesfyourreading.EXPERIMENTALUNCERTAINTYDefinition:Theexperimentaluncertaintyistheestimatedamountbywhichameasureme

7、ntmightbeinerr.E.Whenaddinganuncertaintytoameasurementtheuncertaintygoesafterthemeasuredvaluebutbefetheunit.NOTE:Iftheuncertaindigitisinthefirstdecimalplacetheuncertaintywillbeinthefirstdecimalplacealso.INTERPRETATIONOFU

8、NCERTAINTIESIMPTANT:Theplacevalue(tensunitsfirstdecimaletc.)oftheexperimentaluncertaintythefirstuncertaindigitofameasurementmustagreewitheachother.F.NMALLYUSEUNCERTAINTIESTOTHENEAREST0.1OFTHESMALLESTUNNUMBEREDSUBDIVISION

9、.Ifyoucanonlyestimateavaluetothenearest0.2even0.5ofthesmallestunnumberedsubdivisionfeelfreetodosobutbepreparedjustify(b)Liquidsconfmtotheshapesoftheircontainersexperienceonlyslightchangesinvolumewhenheatedsubjectedtopres

10、sure.(c)Gasesconfmtotheshapesoftheircontainersexperiencedrasticchangesinvolumewhenheatedsubjectedtopressure.Aninvestigationof:vappressureevapationrateviscositygascompressibility.III.3Theclassificationofmatter1.AHOMOGENEO

11、USsubstanceissubstanceconsistingofonlyonephase.Examples:airwatersaltwaterapieceofiron.2.AHETEROGENENOUSsubstanceisasubstanceconsistingofmethanonephase.Examples:ahumanbeingapencil.gravel3.APURESUBSTANCEisasubstancethatish

12、omogeneoushasanunchangeablecomposition.Examples:sugarwatercopperiron4.AMIXTUREisasystemmadeupoftwomesubstancesuchthattherelativeamountsofeachsubstancecanbeVARIED.Examples:saltdissolvedinwateralcoholdissolvedinwater“Mixtu

13、re”isageneraltermwhichincludesbothheterogeneousmixtures(betterknownas“mechanicalmixtures”)homogeneousmixtures(betterknownas“solution”).5.AMECHANICALMIXTUREisaheterogeneousmixtureoftwomesubstances.Examples:gravelsironfili

14、ngsapencilNote:ALLHETEROGENEOUSsubstancesareMECHANICALMIXTURESviceideas.6.ASOLUTIONisahomogeneousmixtureoftwomesubstances.Thereareseveraldifferenttypesofsolutions.TypesofsolutionExampleGasingassolutionAir(oxygennitrogene

15、tc.)GasinliquidsolutionSodapopLiquidinliquidsolutionWateralcoholSolidinliquidsolutionSaltwaterSolidinliquidsolutionAlloys(metalsmeltedtogether)7.AsdefinedpreviouslyanELEMENTisasubstancewhichcannotbeseparatedintosimplersu

16、bstancesasaresultofanychemicalprocess.Inotherwdsanelementisapuresubstanceinwhichalltheatomsareofthesametypes.8.ACOMPOUNDisapuresubstancemadeoftwometypesofatoms.Onlyonetypeofmoleculeispresentinacompound.Thedifferenceinphy

溫馨提示

  • 1. 本站所有資源如無特殊說明，都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等，如果需要附件，請聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙，網(wǎng)頁內(nèi)容里面會有圖紙預(yù)覽，若沒有圖紙預(yù)覽就沒有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 眾賞文庫僅提供信息存儲空間，僅對用戶上傳內(nèi)容的表現(xiàn)方式做保護處理，對用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯，并不能對任何下載內(nèi)容負責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容，請與我們聯(lián)系，我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時也不承擔(dān)用戶因使用這些下載資源對自己和他人造成任何形式的傷害或損失。

評論

0/150

提交評論