Cov koob txhaj tshuaj pov tseg - Cov ntawv ntxiv 1
Kev npaj ntawm ethylene oxide residual kua
0.1mol / L hydrochloric acid: dilute 9ml hydrochloric acid rau 1000ml.
0.5% periodate tov: hnyav 0.5g ntawm periodate thiab dilute mus rau 100ml.
Sodium thiosulfate tov: hnyav 1g ntawm sodium thiosulfate thiab dilute rau 100ml.
10% sodium sulfite tov: hnyav 10. 0g anhydrous sodium sulfite, yaj nws thiab dilute nws mus rau 100ml.
Magenta sulfurous acid test tov: hnyav 0.1g ntawm fuchsin yooj yim thiab ntxiv 120ml dej kub kom yaj nws.Tom qab txias, ntxiv 20ml ntawm 10% sodium sulfite tov thiab 2ml ntawm hydrochloric acid nyob rau hauv qhov tsaus ntuj.Cov tshuaj ntsuam xyuas yuav tsum tsis muaj xim.Yog tias pom tias muaj xim liab, nws yuav tsum tau npaj dua.
Ethylene glycol txheem npaj cov tshuaj: coj ib qho chaw qhuav qhuav thiab ntxuav 50ml ntim ntim, ntxiv txog 30ml dej, ntsuas nws kom raug, noj 0.5ml ethylene glycol, sai sai ntxiv rau hauv lub raj mis, co nws, hnyav, qhov sib txawv ntawm cov ethylene glycol. ob qhov hnyav yog qhov hnyav uas muaj nyob rau hauv cov tshuaj, ntxiv dej rau qhov ntsuas, sib tov, thiab xam nws cov concentration raws li cov qauv hauv qab no:
C＝W/50 × ib txhiab
C: Glycol txheem Tshuag tshuaj concentration g / l;
W: Qhov hnyav ntawm ethylene glycol hauv cov kua g
Ethylene glycol txheem tov: kom raug 1.0ml ntawm cov qauv Tshuag tov, thiab dilute rau 1000ml nrog dej.
Kev npaj ntawm yooj yim oxidized reagent:
a.Dilute sulfuric acid (20%): Noj H2SO4128ml, maj mam txhaj 500mL, thiab dilute mus rau 1000mL tom qab txias.
b.Starch qhia: noj 0.5g ntawm soluble starch, dissolve nws nyob rau hauv 100ml dej, tshav kub thiab boil nws, thiab ces txias nws rau standby (nws yuav tsum tau npaj tshiab thaum nws yog siv ib ntus)
c.Potassium permanganate daws: noj 3.3gKMnO4, ntxiv 1050ml dej, boil rau 15 feeb, ntxiv dej rau 1050ml, cia nws sawv ntsug rau ntau tshaj ob hnub tom qab sealing, lim nws nrog microporous iav funnel, co nws, thiab calibrate nws concentration.
Calibration: Siv 0.25g ntawm kev siv sodium oxalate qhuav kom qhov hnyav ntawm 1050C, ntsuas kom raug, ntxiv 100ml ntawm sulfuric acid tov (8 + 92) thiab do kom dissolve nws.Ceev nrooj ntxiv 25ml ntawm KMnO4 tus qauv kev daws teeb meem kom tau calibrated rau hauv cov tshuaj los ntawm buret.Tom qab fading, kub nws mus rau 650C thiab txuas ntxiv titrating kom txog thaum cov tshuaj hloov xim liab thiab tseem tsis hloov rau 30s.Thaum kawg ntawm titration, qhov kev daws teeb meem yuav tsum tsis txhob qis dua 550C, thiab qhov kev kuaj dawb yuav tsum tau ua tib lub sijhawm.Txhua 6.7mg ntawm sodium oxalate yog sib npaug rau 1ml ntawm 0.02mol / L KMnO4 txheem tov.Qhov tseeb concentration ntawm cov tshuaj no yog xam raws li kev noj cov tshuaj no thiab tus nqi ntawm sodium oxalate noj.
d.C (KMnO4) = 0.002 mol / L: Siv 0.02 mol / L KMnO4 thiab ntxiv dej kom dilute nws 10 zaug ua ntej siv
e.Sodium thiosulfate (0.1 mol / L): hnyav 26g Na2S2O3.5H2O los yog 16g anhydrous Na2S2O3, ntxiv 0.2g anhydrous sodium carbonate, yaj hauv 1000ml dej, maj mam boil nws rau 10min, txias nws, ntxiv dej rau 1000ml, lim nws tom qab. lub lis piam, thiab calibrate nws concentration.
Calibration: hnyav 0.18g ntawm siv poov tshuaj dichromate qhuav ntawm 1200C kom qhov hnyav tas li.Ntsuas qhov tseeb.Muab tso rau hauv ib lub khob ntsuas iodine, yaj hauv 25 ml dej, ntxiv 2 g ntawm poov tshuaj iodide thiab 20 ml ntawm dilute sulfuric acid (20%), co zoo, muab tso rau hauv qhov chaw tsaus rau 10 feeb, ntxiv 150ml dej, titrate nws. Nrog rau kev npaj Na2S2O3 tov [c (Na2S2O3) ＝ 0.1 mol / L], ntxiv 2ml ntawm starch indicator solution (10g/L) ntawm qhov kawg taw tes, txuas ntxiv titrating kom txog thaum cov tshuaj hloov ntawm xiav mus rau ci ntsuab, thiab ua dawb paug kuaj ntawm tib lub sijhawm.Txhua 1 ml ntawm Na2S2O3 (0.1 mol / L) yog sib npaug rau 4.9031mg ntawm potassium dichromate.Qhov concentration ntawm cov tshuaj no yog xam raws li kev noj cov tshuaj no thiab tus nqi ntawm cov poov tshuaj dichromate noj.
f.C (Na2S2O3) ＝ 0.01 mol/L: dilute 0.1 mol/L Na2S2O3 nrog cov tshiab boiled thiab txias dej ua ntej sawv 10 zaug.
Post lub sij hawm: Oct-04-2022
