Cov ntsev muab faib ua nruab nrab, acidic, yooj yim, ob npaug thiab sib xyaw. Tag nrho cov ntawm lawv yog dav siv nyob rau hauv lub neej txhua hnub, tab sis txawm ntau - nyob rau hauv kev lag luam. Kev nkag siab txog kev faib cov ntsev ua rau nws nkag siab cov ntsiab lus ntawm chemistry.
Yuav ua li cas cais cov ntsev
Ua ntej, cia peb txhais cov ntsev. Lawv yog cov tshuaj sib xyaw ua ke uas cov hlau atom txuas nrog cov acidic residue. Tsis zoo li lwm cov chav kawm ntawm cov tshuaj, cov ntsev yog cov yam ntxwv ntawm cov tshuaj ionic.
Cov neeg sawv cev ntawm cov chav kawm no tau muab faib ua ntau pawg nrog cov yam ntxwv tshwj xeeb.
Ntau ntsev
Cov ntsev nruab nrab tsuas muaj cov cations ntawm qee cov hlau thiab cov kua qaub seem. Raws li ib qho piv txwv ntawm cov tebchaw, sodium chloride, potassium sulfate tuaj yeem hais tau. Nws yog cov pab pawg no uas suav tias yog feem ntau hauv lub ntiaj teb crust. Ntawm txoj hauv kev kom tau txais lawv, peb nco ntsoov cov txheej txheem nruab nrab ntawm cov kua qaub thiab lub hauv paus.
Acid ntsev
Cov pab pawg no muaj cov hlau, hydrogen, thiab tseem muaj cov kua qaub. Polybasic acids tsim cov tshuaj sib xws: phosphoric, sulfuric, carbonic. Raws li ib tug piv txwv ntawm ib tug acid ntsev muaj ib tug davKev faib tawm hauv lub neej txhua hnub, sodium bicarbonate (baking soda) tuaj yeem sau tseg. Cov tshuaj no tau txais los ntawm kev sib cuam tshuam ntawm nruab nrab ntsev thiab cov kua qaub.
Basic ntsev
Cov tebchaw no muaj cov hlau cations, ib pawg hydroxyl, nrog rau cov anions ntawm cov kua qaub seem. Ib qho piv txwv ntawm cov ntsev yooj yim yog calcium hydroxochloride.
Ob chav ntsev hais txog qhov muaj ob lub hlau uas hloov cov hydrogen hauv cov kua qaub. Kev tsim cov tshuaj ntawm ib qho zoo sib xws yog cov yam ntxwv ntawm polybasic acids. Piv txwv li, nyob rau hauv sodium poov tshuaj carbonate, ob active hlau muaj nyob rau hauv ib zaug. Ob chav sib xyaw ntsev yog qhov tseem ceeb rau kev lag luam tshuaj, dav siv hauv lub neej txhua hnub.
Ntawm cov ntsev sib xyaw
Ob chav ntsev ntawm poov tshuaj thiab sodium yog pom nyob rau hauv cov xwm nyob rau hauv daim ntawv ntawm sylvinite. Potassium kuj tuaj yeem tsim cov ntsev sib xyaw nrog txhuas.
Mixed (ob) ntsev yog cov khoom sib xyaw uas muaj ntau yam anions lossis cations. Piv txwv li, tshuaj dawb hauv nws cov muaj pes tsawg leeg muaj anion ntawm hypochlorous thiab hydrochloric acid.
Ob chav ammonium ntsev yog qhov txaus siab tshwj xeeb. Feem ntau ntawm cov khoom tau txais yog siv los ua cov ntxhia chiv.
Tau txais ob ammonium ntsev yog ua los ntawm kev sib cuam tshuam ntawm ammonia nrog polybasic acids. Diammonium phosphates yog nyob rau hauv kev thov hauv kev tsim hluav taws kub retardants (hluav taws kub retardants). Ob chav ntsev uas tsis muaj impurities,xav tau nyob rau hauv kev lag luam tshuaj thiab zaub mov.
Ammonium zinc thiab magnesium phosphates yog qhov tseem ceeb ntawm kev lag luam. Vim lawv qhov tsis zoo solubility hauv dej, cov ntsev no ua haujlwm raws li cov nplaim hluav taws kub nyhiab hauv cov xim thiab cov yas.
Cov ntsev ob no yog tsim rau impregnating fabrics thiab ntoo, tiv thaiv qhov chaw los ntawm high humidity. Hlau thiab txhuas ammonium phosphates yog cov cuab yeej zoo heev los tiv thaiv cov qauv hlau los ntawm cov txheej txheem corrosion ntuj.
Piv txwv ntawm ob ntsev ntawm cov txuj ci tseem ceeb tuaj yeem muab rau hlau thiab zinc. Lawv yog cov chaw yug me nyuam rau cov poov xab loj hlob, hauv kev thov hauv kev tsim cov khoom sib tw, tsim cov ntaub ntawv insulating, mica.
Tau txais
Ob chav ammonium ntsev yog tau los ntawm thermal saturation ntawm phosphoric acid nrog ammonia thiab ib qho alkali. Kev txaus siab ntawm kev lag luam yog dimonium phosphate. Nws yog tsim los ntawm kev kho cua sov nrog ammonia ntawm phosphoric acid. Txhawm rau kom ua tiav cov txheej txheem, qhov kub ntawm li 70 degrees Celsius yuav tsum tau ua. Cov thev naus laus zis suav nrog kev tsim cov txhuas thiab hlau phosphates nyob rau hauv daim ntawv ntawm precipitates, uas kuj pom lawv daim ntawv thov kev lag luam.
Qee qhov teeb meem tshwm sim nrog cov npe ntawm ob lub ntsev vim qhov tseeb tias lawv muaj cov acidic residues, lossis ob cations.
Magnium ammonium phosphate yog nyob rau hauv kev thov hauv kev lag luam tshuaj, yog li cov thev naus laus zis ntawm nws cov tsim muaj qee yam nta. Ua tawm neutralization nrog gaseous ammonia extractionphosphoric acid, uas yog tov nrog magnesium phosphate.
Complex compounds
Muaj qee qhov sib txawv ntawm cov ntsev thiab ob chav ntsev. Cia peb sim ua kom paub cov yam ntxwv ntawm cov ntsev complex. Lawv muaj pes tsawg leeg yog xav tias muaj ib tug complex ion, uas yog nyob rau hauv lub square brackets. Tsis tas li ntawd, cov tshuaj no muaj cov tshuaj complexing (central ion). Nws yog ib puag ncig los ntawm cov khoom hu ua ligands. Cov ntsev nyuaj yog tus cwj pwm los ntawm kev sib cais stepwise. Thawj kauj ruam yog tsim ib tug complex ion nyob rau hauv daim ntawv ntawm ib tug cation los yog anion. Tsis tas li ntawd, muaj ib feem dissociation ntawm complex ion rau hauv ib cation thiab ligands.
Ntawm nomenclature ntawm ntsev
Muab hais tias muaj ntau ntau hom ntsev, lawv cov nomenclature yog txaus siab. Rau nruab nrab ntsev, lub npe yog tsim nyob rau hauv lub hauv paus ntawm anion (chloride, sulfate, nitrate), uas lub Lavxias teb sab lub npe ntawm cov hlau yog ntxiv. Piv txwv li, CaCO3 yog calcium carbonate.
Acidic ntsev yog tus cwj pwm los ntawm kev ntxiv cov prefix hydro-. Piv txwv li, KHCO3 yog potassium bicarbonate.
Lub npe ntawm cov ntsev yooj yim txhais tau hais tias siv cov lus ua ntej hydroxo-. Yog li, Al (OH) 2Cl ntsev hu ua aluminium dihydroxochloride.
Thaum sau ob lub ntsev uas muaj ob lub cations, thawj lub npe anion, ces sau ob lub hlau uas muaj nyob rau hauv cov compound.
Ntau lub npe yog ib yam rau cov tebchaw nyuaj. Hauv chemistry, muaj ib ntu tshwj xeeb uas cuam tshuam nrog kev kawm txog cov ntsev xws li ntsev.
YogTxhawm rau txheeb xyuas cov khoom ntawm lub cev ntawm cov neeg sawv cev sib txawv ntawm ob lub ntsev, nws tuaj yeem raug sau tseg tias lawv sib txawv hauv lawv lub peev xwm yaj hauv dej. Ntawm cov ntsev ob, muaj cov piv txwv ntawm cov khoom uas muaj cov solubility zoo, piv txwv li, sodium chloride, potassium chloride. Ntawm cov ntsiab lus tsis zoo soluble, ob lub ntsev ntawm phosphoric thiab silicic acids tuaj yeem raug xam.
Hais txog cov khoom siv tshuaj, cov ntsev ob npaug zoo ib yam li cov khoom qub (nruab nrab), lawv muaj peev xwm cuam tshuam nrog cov kua qaub thiab lwm cov ntsev.
Nitrates thiab ammonium ntsev dhau los ntawm thermal decomposition, tsim ntau yam tshuaj tiv thaiv.
Nyob rau hauv cov ntaub ntawv ntawm electrolytic dissociation ntawm xws compounds, anions ntawm residue thiab hlau cations yuav tau. Piv txwv li, thaum poov tshuaj alum decomposes rau hauv ions, txhuas thiab poov tshuaj cations, nrog rau sulfate ions, tuaj yeem pom hauv cov tshuaj.
Sib cais ntsev sib xyaw
Muab cov khoom siv ntuj tsim muaj ob lub hlau ib zaug, nws tsim nyog los cais lawv. Ntawm ntau txoj hauv kev los cais cov ntsev sib tov, fractional crystallization tuaj yeem paub qhov txawv. Txoj kev no suav nrog qhov ua ntej melting ntawm ob lub ntsev, nws qhov kev faib ua ntu zus mus rau hauv cov tebchaw sib txawv, tom qab ntawd crystallization. Qhov kev xaiv no rau kev sib cais sib xyaw yog txuam nrog cov yam ntxwv ntawm lub cev ntawm cov khoom. Thaum sib cais sib tov los ntawm kev siv tshuaj, cov tshuaj reagents raug xaiv uas zoo rau qee yam cations lossis anions. Tom qab nag lossis daus ntawm ib qho ntawm lawv qhov chaw ntawm ob lub ntsev, cov nag lossis daus raug tshem tawm.
Yog tias tsim nyog, sib cais ntawm peb lub ntsiab luscov tshuab uas muaj cov theem khoom, nrog rau emulsions, centrifugation yog nqa tawm.
Zoo kawg
Ob chav ntsev txawv ntawm lwm hom ntsev los ntawm muaj ob lub hlau hauv cov mis. Nyob rau hauv nws daim ntawv ntshiab, cov tebchaw no tsis tshua siv, feem ntau lawv tau pib sib cais los ntawm kev siv lub cev lossis tshuaj, thiab tsuas yog tom qab ntawd siv ntau qhov chaw ntawm kev tsim khoom. Ob chav ntsev kuj siv rau hauv kev lag luam tshuaj raws li qhov chaw ntawm ntau cov tshuaj xav tau.
