Methyl red ndi methylene blue: mmene chizindikiro cha Tashiro chimagwirira ntchito

Chizindikiro chosakaniza cha Tashiro chimaphatikiza methyl red ndi methylene blue kuti zikhale zosavuta kuona kusintha pa titration ya asidi ndi besi. Methyl red ndi imene imasintha malinga ndi pH; methylene blue imasintha kusiyana kwa mitundu yomwe imaoneka. Kusintha kuchoka pa wobiriwira kupita pa wofiirira m’chisakanizochi sikuyenera kutanthauzidwa kuti utoto wabuluu ukukumana ndi reduction yake yodziwika bwino n’kukhala wopanda mtundu.

Kapangidwe ka chisakanizo n’kofunika. Dzina la pabotolo limasonyeza gulu la zizindikiro, koma labotale imafunikabe kudziwa zosakaniza zake, kusintha kwake kolembedwa, ndi njira yofotokoza nthawi yosiya kuwonjezera mankhwala a titration.

Zimene utoto uliwonse umathandiza

Methyl red ndi chizindikiro cha asidi ndi besi. Maonekedwe ake okhala ndi proton ndi opanda proton amayamwa kuwala kooneka mosiyanasiyana, choncho kusintha kwa kuchuluka kwa maonekedwe awiriwa kumapangitsa mtundu kusintha pamene pH ikusintha. Mwachitsanzo, Sigma-Aldrich imatchula kusintha kuchoka pa wapinki kupita pa wachikasu pa pH 4.2–6.2 kwa methyl red yake yogwiritsidwa ntchito pa kuyesa.

Kuwonjezera utoto wabuluu kumasintha zimene diso limaona: mbali yofiira imaoneka yofiirira kwambiri, pamene mbali yachikasu ikasakanikirana ndi buluu imaoneka yobiriwira. Izi nthawi zambiri zimatchedwa kusintha maonekedwe a chizindikiro. Kusiyana kofunika kuli pakati pa chigawo chimene chimasintha malinga ndi kuchuluka kwa asidi ndi chigawo chimene chimasintha maonekedwe ake. Kusakaniza mitundu ya utotoyi sikusandutsa methylene blue kukhala choyezera pH chogwira ntchito pa zinthu zonse.

Yerekezerani zochitika zitatuzi musanatanthauzire mtundu:

Mzere womalizawu ukufotokoza kuyesa kosiyana. Mu chiwonetsero cha botolo labuluu cha Oxford, glucose m’malo a alkaline imachititsa reduction ya methylene blue n’kuipangitsa kukhala yopanda mtundu, ndipo oxygen yowonjezedwa imabwezeretsa mtundu wabuluu. Zochitika zimenezi zimafotokoza kuzungulira kwa redox, osati kusintha kwa asidi ndi besi komwe Tashiro cholinga chake ndi kusonyeza. Kusiyana kumeneku mwatsatanetsatane kumafotokozedwa pa sayansi ya redox ya methylene blue.

Kapangidwe kolembedwa ndi mbali imene mtundu umasinthira

Chikalata chaukadaulo cha ITW Reagents cha mankhwala 282430, chosindikizidwa cha 5 cha Okutobala 2018, chimatchula 100 mg ya methyl red ndi 50 mg ya methylene blue, pamodzi ndi 10.4 mL ya madzi ndi ethanol yopanda madzi yokwanira kupanga 100 mL. Chimatchula kuti mankhwalawa ndi a titration ya ammonia ndipo chimalemba kuti amakhala ofiira-wofiirira pa pH 4.4 ndi obiriwira pa pH 5.8.

Izi zimapereka chithunzi chotsatirachi, chogwirizana ndi kapangidwe kameneka:

pH 4.4, wofiira-wofiirira → pH ikukwera → pH 5.8, wobiriwira

pH 5.8, wobiriwira → pH ikutsika → pH 4.4, wofiira-wofiirira

Muvi umafotokoza mbali ya kusintha kudutsa m’dera limene chizindikirocho chimasintha. Sikuti ukusonyeza kuti mbali ina ya derali ndiyo yoyenera kuimilira pa kuyesa kulikonse. Chikalatacho sichitchula pomalizira penipeni pomwe mtundu umakhala wotuwa, choncho pH ya pomalizira potuwa yogwira ntchito nthawi zonse singatengedwe m’mafotokozedwe amenewa.

Dziwaninso kuti mtundu wobiriwira pa pH 5.8 udakali wa malo a asidi m’madzi nthawi zambiri. Kungotchula mitunduyo kuti “asidi” ndi “alkaline” kungabisike mfundo imeneyi: mbali yobiriwira ndiyo ya pH yokwera kwambiri m’kusinthako, osati umboni wakuti pH ya chitsanzo yapitirira 7.

Zimene titration ya ammonia imayezadi

Chizindikiro chimasonyeza nthawi yowerenga burette. Kuchuluka kwa chinthu choyesedwacho kumachokera pa kuchuluka kwa mankhwala a titration omwe agwiritsidwa ntchito, mphamvu yake yotsimikizidwa, ndi chiŵerengero cha mankhwala amene amachita nawo kusinthana. Mtundu wobiriwira kwambiri, paokha, suyeza kuchuluka kwa ammonia yochulukirapo.

Monga chitsanzo cha njira yeniyeni, EPA Method 350.2 yakale yosindikizidwanso ndi NEMI imasiyanitsa ammonia mwa kuisandutsa nthunzi n’kuisonkhanitsa mu boric acid, ndipo imayesa kuchuluka kwake mwa titration ndi sulfuric acid ya mphamvu yotsimikizidwa. Chizindikiro chake chosakaniza chimagwiritsa ntchito magawo awiri a madzi oyambirira a 0.2% methyl red ndi gawo limodzi la madzi oyambirira a 0.2% methylene blue, zonse zili mu 95% ethanol. Njirayo imalangiza woyesa kuti ayerekeze pomalizira ndi chitsanzo chopanda chinthu choyesedwa, chokhala ndi madzi ndi boric acid mu kuchuluka kofanana ndi kogwiritsidwa ntchito poyesa.

Njira yosakanizira imeneyi ndi kapangidwe ka mankhwala ogulitsidwa kotchulidwa pamwambapa zili ndi chiŵerengero chofanana cha kulemera kwa mitundu ya utoto, koma zimasiyana pa mphamvu ya utoto ndi zosungunulira. Choncho, chiŵerengero chofanana sichili umboni wokwanira wakuti mabotolo awiri angagwiritsidwe ntchito mosinthana. Njirayi imakhudzanso nayitrogeni wa mu ammonia ndipo imanena momveka bwino kuti siyiphatikiza kuyesa nayitrogeni yonse ya Kjeldahl. Kugwiritsa ntchito chizindikiro chofanana sikutanthauza kuti njira ziwiri zoyezera nayitrogeni ndi kuyesa kumodzi.

Gwiritsani ntchito chikalatacho kuti mumvetsetse ndondomeko yoyesera yomwe yafotokozedwa, osati kuganiza kuti chosindikizidwa chake chakale ndicho chimakhazikitsa zofunikira za kupereka zotsatira masiku ano. Njira yomwe labotale yasankha iyenera kutchula chosindikizidwa choyenera kugwiritsidwa ntchito ndi njira zake zotsimikizira ubwino wa kuyesa.

Pomalizira titration ndi pofanana ndendende pa kuchuluka kwa mankhwala ndi zosiyana

IUPAC imatanthauzira titration ndi pomalizira pake potengera kuzindikira kuti kusinthana kwa mankhwala kwatha; pofanana ndendende pa kuchuluka kwa mankhwala ndi pamene kuchuluka kwa mankhwalawo kumagwirizana ndendende malinga ndi kusinthana kwawo. Chizindikiro chooneka chimakhala chothandiza ngati chili pafupi mokwanira ndi pamenepo kuti chikwaniritse cholinga cha njirayo.

Tiyerekeze kuti oyesa awiri akuchita titration ya zitsanzo zofanana. Mmodzi amasiya pamene madziwo akufanana ndi chitsanzo chopanda chinthu choyesedwa chomwe chatchulidwa. Winayo amapitiriza mpaka mtundu wofiirira wamphamvu kwambiri utaoneka. Woyesa wachiwiriyo wasankha pomalizira posiyana ndipo angagwiritse ntchito mankhwala a titration ochulukirapo. Kugwirizana pa dzina la mtundu womaliza sikutsimikizira kugwirizana pa kuchuluka koyezedwa.

N’chifukwa chake zolembedwa zophunzitsira ziyenera kutchula chinthu choyerekezera nacho, mmene kuonera kuyenera kuchitikira, ndi nthawi yomwe mtundu uyenera kukhalabe usanavomerezedwe malinga ndi njirayo. Chithunzi cha pa sikirini chingafotokoze mbali ya kusintha, koma chinthu choyerekezera cha mu labotale ndicho chimakhazikitsa mmene chisankho chimapangidwira pa ntchito yeniyeni.

Kuwunika kofunika musanasinthe chizindikiro kapena kufufuza vuto lake

Gwiritsani ntchito pepala ili mtundu ukamaoneka wolakwika kapena botolo lina likaperekedwa kuti lilowe m’malo mwa loyamba:

Ngati chitsanzo chopanda chinthu choyesedwa sichikupereka zotsatira zoyembekezereka, kapena mtundu ukusintha popanda chifukwa chomveka, tengani zimenezo ngati chifukwa chofufuzira mankhwala oyesera ndi njirayo musanapereke zotsatira. Kuwonjezera utoto mpaka chitsanzo chikaoneka monga mumachidziwira kumasintha mmene kuonerako kukuchitikira ndipo kungabise vuto loyambirira.

Kuti musankhe ntchito yoyenera ya utotowu pa kuyesa kwina, yambani ndi methylene blue pa kuyesa kwa kusanthula mankhwala. Pa titration za Tashiro, sungani pamodzi zolemba za kapangidwe ka utoto, maonekedwe ozindikira pomalizira, ndi mawerengedwe a zotsatira za kuyesa.