2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
aryl halides … diazonium ions tau npaj los ntawm diazotization, txheej txheem uas cov tshuaj tsw qab amine (ArNH 2) tau kho nrog qhov chaw ntawm nitrous acid Nitrous acid Nitrous acid , (HNO2), ib qho tsis ruaj khov, tsis muaj zog acidic compound uas tau npaj tsuas yog hauv daim ntawv txias, dilute daws. Nws yog ib qho tseem ceeb hauv chemistry hauv kev hloov amines rau hauv diazonium tebchaw, uas yog siv los ua azo dyes. https://www.britannica.com › science › nitrous-acidY
Nitrous acid | chemical compound | Britannica
(HNO2) . Feem ntau qhov no suav nrog ntxiv sodium nitrite (NaNO2) rau cov kua qaub aqueous uas muaj cov amine.
Thaum twg tshuaj tsw qab amine tseem ceeb?
(c) Sandmeyer cov tshuaj tiv thaiv Thaum thawj cov tshuaj tsw qab amine, yaj lossis raug tshem tawm hauv cov dej txias aqueous ntxhia acid, kho nrog sodium nitrite, diazonium ntsev yog tsim (Teb 13. Chav Kawm XII).
Thaum thawj cov tshuaj tsw qab yog kho nrog nano2?
Thaum thawj cov tshuaj tsw qab amine raug kho nrog NaNO_(2) + HCI ntawm 0^(@)-5^(@)C, diazonium ntsev yog tsim thiab cov tshuaj tiv thaiv hu ua diazo cov tshuaj tiv thaiv. Nyob rau hauv cov tshuaj tiv thaiv mineral acid yuav tsum tau ntxiv los tiv thaiv coulping cov tshuaj tiv thaiv ntawm diazonium ntsev nrog ntau tshaj aryl amine.
Dab tsi yog diazotization cov tshuaj tiv thaiv ntawm amine?
txheej txheem ntawm hloov pauv ntawm thawjaromatic amines rau hauv nws cov ntsev diazonium yog hu ua diazotization. Diazonium ntsev yog cov khoom nruab nrab tseem ceeb uas tuaj yeem ua rau muaj kev sib txuas ua ke los tsim cov azo dyes thiab cov tshuaj electrophilic hloov pauv los qhia cov pab pawg ua haujlwm.
Yuav ua li cas ntsev yog siv rau diazotization ntawm aromatic amines?
Cov nitrosation ntawm thawj amines aromatic nrog nitrous acid (tsim nyob rau hauv situ los ntawm sodium nitrite thiab ib tug muaj zog acid, xws li hydrochloric acid, sulfuric acid, los yog HBF 4) ua rau diazonium ntsev, uas tuaj yeem cais tau yog tias qhov kev tawm tsam tsis yog nucleophilic.
Pom zoo:
Puas kho kho mob rau txhua tus ua rau tus kws kho mob tsis txaus?
Ib daim ntawv tshaj tawm los ntawm FTI Kev Sib Tham pom tias Medicare rau Txhua Tus yuav txo qis qhov kev npajtus kws kho mob hauv Asmeskas xyoo 2050 los ntawm kwv yees li 44,000, suav nrog ntau dua 10, 000 tus kws kho mob thawj zaug kws kho mob.
Nyob rau hauv angiosperms pollen yog tsim nyob rau hauv anthers ib feem ntawm?
Nyob rau hauv angiosperms, paj ntoos yog tsim los ntawm anthers ntawm the stamens hauv paj. Hauv gymnosperms, nws yog tsim nyob rau hauv microsporophylls ntawm microstrobili (txiv neej paj ntoos cones). Pollen muaj ib los yog ntau tshaj cov noob qoob loo thiab ib lub qe qe.
Yuav ua li cas txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau pom kev pom?
Txawm li cas los xij, corneal collagen cross-linking - cov txheej txheem qib siab tau pom zoo los ntawm US Food and Drug Administration (FDA) hauv xyoo 2016 - tuaj yeem txhim kho qhov pom kev hauv cov neeg mob txhua hnub nyoog. Corneal collagen cross-linking (CXL) tsis yog kho rau keratoconus, tab sis nws tuaj yeem pab tiv thaiv tus mob kom tsis txhob mob hnyav.
Nyob rau hauv vernalisation flowering nyob rau hauv cov nroj tsuag yog?
Vernalization (los ntawm Latin vernus, "ntawm lub caij nplooj ntoos hlav") yoginduction ntawm cov nroj tsuag flowering txheej txheem los ntawm raug rau lub caij txias ntawm lub caij ntuj no, los yog los ntawm ib qho khoom sib npaug.
Leej twg detering nyob rau hauv tag nrho cov nyob ntsiag to nyob rau sab hnub poob pem hauv ntej?
Detering yog tus neeg ua liaj ua teb los ntawm Txhua Tus Neeg Tsis Txaus Siabntawm Sab Hnub Poob los ntawm Erich Maria Remarque. Nws muaj siab mos siab muag, tshwj xeeb tshaj yog thaum nws los txog rau nees. Nws muaj kev kub ntxhov loj heev thaum nws hnov cov nees quaj thiab txawm sim tua lawv kom kawg lawv txoj kev txom nyem.
