39.Ni ubuhe busembwa bw'amazi n'ubunyobwa?
Acide y'amazi bivuga ubwinshi bwibintu biri mumazi bishobora gutesha agaciro ibishingwe bikomeye. Hariho ubwoko butatu bwibintu bigize acide: acide ikomeye ishobora gutandukanya burundu H + (nka HCl, H2SO4), acide nkeya itandukanya igice H + (H2CO3, acide organic), numunyu ugizwe na acide ikomeye nishingiro ridakomeye (nka NH4Cl, FeSO4). Acide ipimwa na titre hamwe nigisubizo gikomeye. Acide yapimwe na methyl orange nkikimenyetso mugihe cya titre yitwa methyl orange acide, harimo acide ikorwa nubwoko bwa mbere bwa acide ikomeye nubwoko bwa gatatu bwumunyu wa acide; acide yapimwe na fenolphthalein nkuko ibipimo byitwa acide phenolphthalein, Ni igiteranyo cyubwoko butatu bwavuzwe haruguru bwa acide, bityo nanone bwitwa acide yuzuye. Amazi karemano muri rusange ntabwo arimo acide ikomeye, ariko arimo karubone na bicarubone ikora amazi alkaline. Iyo hari aside iri mumazi, akenshi bivuze ko amazi yandujwe na aside.
Bitandukanye na acide, alkaline yamazi bivuga ubwinshi bwibintu biri mumazi bishobora gutesha aside ikomeye. Ibintu bigize alkalineite harimo ibishingwe bikomeye (nka NaOH, KOH) bishobora gutandukanya burundu OH-, ibishingwe bidakomeye bitandukanya igice OH- (nka NH3, C6H5NH2), hamwe nu munyu ugizwe nibishingwe bikomeye na acide nkeya (nka Na2CO3, K3PO4, Na2S) nibindi byiciro bitatu. Ubunyobwa bupimwa na titre hamwe n'umuti ukomeye wa aside. Ubunyobwa bwapimwe ukoresheje methyl orange nk'ikimenyetso mu gihe cyo gutanga titre ni igiteranyo cy'ubwoko butatu bwavuzwe haruguru, bwitwa alkalinity cyangwa methyl orange alkalinity; alkalinity yapimwe ikoresheje fenolphthalein nkikimenyetso cyitwa fenolphthalein base. Impamyabumenyi, harimo alkalineite yakozwe nubwoko bwa mbere bwibanze kandi igice cya alkaline ikorwa nubwoko bwa gatatu bwumunyu ukomeye wa alkali.
Uburyo bwo gupima acide na alkalineite burimo aside-fatizo yerekana titre na potentiometric titre, muri rusange bihinduka CaCO3 kandi bipimwa muri mg / L.
40.Ni ubuhe bwoko bwa pH bw'amazi?
Agaciro pH ni logarithm mbi yibikorwa bya hydrogène ion mugisubizo cyamazi yapimwe, ni ukuvuga pH = -lgαH +. Ni kimwe mu bipimo bikoreshwa cyane mugikorwa cyo gutunganya imyanda. Mubihe 25oC, iyo pH ifite agaciro ka 7, ibikorwa bya hydrogène ion na hydroxide ion mumazi bingana, kandi kwibandaho ni 10-7mol / L. Muri iki gihe, amazi ntaho abogamiye, kandi agaciro ka pH> 7 bivuze ko amazi ari alkaline. , na pH agaciro<7 means the water is acidic.
Agaciro pH kagaragaza acide nubunyobwa bwamazi, ariko ntishobora kwerekana neza aside na alkaline yamazi. Kurugero, acide ya 0.1mol / L hydrochloric acide na 0.1mol / L acide acide nayo 100mmol / L, ariko agaciro ka pH karatandukanye cyane. PH agaciro ka 0.1mol / L hydrochloric acide ni 1, mugihe pH agaciro ka 0.1 mol / L acide acide acide ni 2.9.
41. Nubuhe buryo bukoreshwa muburyo bwo gupima agaciro pH?
Mu musaruro nyirizina, kugirango ubashe kumva vuba kandi byoroshye impinduka zagaciro ka pH kumazi y’amazi yinjira mu ruganda rutunganya amazi y’amazi, uburyo bworoshye ni ukupima hafi nimpapuro zipimisha pH. Kubwamazi atagira ibara adafite umwanda wahagaritswe, uburyo bwa colimetric burashobora kandi gukoreshwa. Kugeza ubu, igihugu cyanjye gisanzwe cyo gupima pH agaciro k’amazi nuburyo bwa potentiometrike (GB 6920-86 ibirahuri bya electrode). Mubisanzwe ntabwo bigira ingaruka kumabara, guhindagurika, ibintu bya colloidal, okiside, no kugabanya ibintu. Irashobora kandi gupima pH y'amazi meza. Irashobora kandi gupima agaciro ka pH kumazi mabi yinganda yanduye kurwego rutandukanye. Ubu kandi nuburyo bukoreshwa cyane mugupima agaciro ka pH mubihingwa byinshi bitunganya amazi mabi.
Ihame ryo gupima potentiometrike y agaciro ka pH nugushaka ubushobozi bwa electrode yerekana, ni ukuvuga agaciro ka pH, mugupima itandukaniro rishobora kuba hagati yikirahure cya electrode yikirahure hamwe na electrode yerekana ifite ubushobozi buzwi. Ubusanzwe electrode ikoresha electrode ya Calomel cyangwa electrode ya Ag-AgCl, hamwe na electrode ya calomel niyo ikoreshwa cyane. Intangiriro ya pH potentiometero ni DC amplifier, yongerera imbaraga imbaraga zatewe na electrode ikayerekana kumutwe wa metero muburyo bwimibare cyangwa yerekana. Potentiometero isanzwe ifite ibikoresho byindishyi zubushyuhe kugirango bikosore ingaruka zubushyuhe kuri electrode.
Ihame ryakazi rya metero ya pH kumurongo ukoreshwa mubihingwa bitunganya amazi ni uburyo bwa potentiometric, kandi ingamba zo gukoresha zikoreshwa cyane cyane nka metero ya laboratoire pH. Ariko, kubera ko electrode ikoreshwa idahwema gushiramo amazi mabi cyangwa ibigega bya aerasiya nahandi hantu harimo amavuta menshi cyangwa mikorobe nyinshi mugihe kirekire, usibye gusaba metero pH kuba ifite ibikoresho byogusukura byikora kuri electrode, nigitabo isuku nayo irakenewe hashingiwe kumiterere yubuziranenge bwamazi nuburambe bwo gukora. Mubisanzwe, metero pH ikoreshwa mumazi yinjira cyangwa ikigega cya aeration isukurwa nintoki rimwe mubyumweru, mugihe metero pH ikoreshwa mumazi yanduye irashobora gusukurwa nintoki rimwe mukwezi. Kuri metero pH zishobora gupima icyarimwe ubushyuhe na ORP nibindi bintu, bigomba kubungabungwa no kubungabungwa hakurikijwe ingamba zikoreshwa zisabwa mumikorere yo gupima.
42.Ni izihe ngamba zo gupima agaciro ka pH?
PotPotentiometero igomba guhora yumutse kandi itagira umukungugu, ikoreshwa buri gihe kugirango ibungabungwe, kandi igice cyinjiza cyinjira mugice cya electrode kigomba guhorana isuku kugirango birinde ibitonyanga byamazi, ivumbi, amavuta, nibindi byinjira. Wemeze neza ko ukoresha imbaraga za AC. Potentiometero zigendanwa zikoresha bateri zumye zigomba gusimbuza bateri buri gihe. Muri icyo gihe, potentiometero igomba guhora ihindurwamo kandi ikanashyirwa kuri zeru kugirango ikorwe kandi ikorwe. Iyo bimaze gukosorwa neza, ingingo ya zeru ya potentiometero hamwe na kalibrasi hamwe nubugenzuzi bwibibanza ntibishobora kuzunguruka uko bishakiye mugihe cyizamini.
WaterAmazi akoreshwa mugutegura igisubizo gisanzwe cya buffer no kwoza electrode ntigomba kuba irimo CO2, ifite agaciro ka pH hagati ya 6.7 na 7.3, hamwe nubushobozi buri munsi ya 2 μs / cm. Amazi yatunganijwe na anion hamwe na cation yo guhana birashobora kuzuza iki gisabwa nyuma yo guteka no kureka bikonje. Igisubizo gisanzwe cya buffer kigomba gufungwa no kubikwa mumacupa yikirahure ikomeye cyangwa icupa rya polyethylene, hanyuma bikabikwa muri firigo kuri 4oC kugirango ubuzima bwa serivisi bube. Niba bibitswe mu kirere cyangwa ku cyumba cy'ubushyuhe, ubuzima bwa serivisi muri rusange ntibushobora kurenga Ukwezi 1, buffer yakoreshejwe ntishobora gusubizwa icupa ryabitswe kugirango ikoreshwe.
⑶ Mbere yo gupimwa kumugaragaro, banza urebe niba igikoresho, electrode, na buffer zisanzwe ari ibisanzwe. Kandi metero ya pH igomba guhinduka buri gihe. Mubisanzwe kalibrasi yinzinguzingo ni kimwe cya kane cyangwa igice cyumwaka, kandi uburyo bubiri bwa kalibibasi bukoreshwa muburyo bwo guhitamo. Nukuvuga, ukurikije pH agaciro kurugero rwicyitegererezo kigomba kugeragezwa, ibisubizo bibiri bya buffer ibisubizo hafi yacyo byatoranijwe. Mubisanzwe, itandukaniro ryagaciro rya pH hagati yibi bisubizo byombi bigomba kuba byibuze birenze 2. Nyuma yo guhagarara hamwe nigisubizo cya mbere, ongera ugerageze igisubizo cya kabiri. Itandukaniro riri hagati yerekana ibisubizo bya potentiometero nigiciro gisanzwe cya pH cyumuti wa kabiri wa buffer igisubizo ntigomba kurenza 0.1 pH igice. Niba ikosa rirenze 0.1 pH igice, igisubizo cya gatatu gisanzwe kigomba gukoreshwa mugupima. Niba ikosa riri munsi ya 0.1 pH muri iki gihe, birashoboka cyane ko ikibazo cyakemutse cya kabiri. Niba ikosa riracyari hejuru ya 0.1 pH, hari ibitagenda neza kuri electrode kandi electrode igomba gutunganywa cyangwa gusimburwa nindi nshya.
HenIyo usimbuye buffer isanzwe cyangwa icyitegererezo, electrode igomba kwozwa byuzuye namazi yatoboye, hanyuma amazi afatanye na electrode agomba kwinjizwa nimpapuro zungurura, hanyuma akakaraba hamwe nigisubizo cyo gupimwa kugirango akureho ingaruka. Ibi nibyingenzi mugukoresha za buffers zintege nke. Ibi nibyingenzi cyane mugihe ukoresheje ibisubizo. Iyo upimye agaciro ka pH, igisubizo cyamazi kigomba gukangurwa muburyo bukwiye kugirango igisubizo kibe kimwe kandi kigere kuburinganire bwa electrochemic. Mugihe usoma, kubyutsa bigomba guhagarikwa kandi bikemererwa guhagarara umwanya muto kugirango ibyasomwe bihamye.
⑸ Mugihe upima, banza kwoza electrode ebyiri witonze ukoresheje amazi, hanyuma woge hamwe nicyitegererezo cyamazi, hanyuma winjize electrode mukibuto gito kirimo icyitegererezo cyamazi, uzunguze inzoga witonze ukoresheje amaboko yawe kugirango icyitegererezo cyamazi kibe kimwe, hanyuma wandike pH agaciro nyuma yo gusoma ihamye.
Igihe cyo kohereza: Ukwakira-26-2023
