Sodium Cyanide: Kev Taw Qhia rau Nws Cov Khoom Siv Tshuaj thiab Cov Txheej Txheem Txheej Txheem

sodium cyanide (NaCN) yog ib qho tseem ceeb heev inorganic compound nrog ntau yam kev siv thoob plaws ntau yam kev lag luam, tab sis nws kuj yog qhov tsis zoo rau nws cov tshuaj lom heev. To taub nws Tshuaj lom neeg thiab cov txheej txheem tshuaj tiv thaiv yog qhov tseem ceeb rau kev nyab xeeb, kev siv tau zoo, thiab Kev tiv thaiv ib puag ncig. Qhov kev tshaj tawm blog no lub hom phiaj los muab cov ntsiab lus dav dav ntawm cov haujlwm no.

Chemical Properties ntawm Sodium Cyanide

Sodium cyanide yog ib qho dawb, crystalline khoom uas yog soluble hauv dej, ua kom muaj zog alkaline. Nws solubility hauv dej yog ntaus nqi los ntawm ionic xwm ntawm lub compound. Nyob rau hauv lub xeev khoom, NaCN muaj sodium cations (Na⁺) thiab cyanide anions (CN⁻) tuav ua ke los ntawm ionic bonds. Thaum yaj nyob rau hauv dej, cov ions no dissociate, tso cai rau cov compound kom yooj yim yaj. Cov txheej txheem tawg tuaj yeem sawv cev los ntawm qhov sib npaug: NaCN(s) → Na⁺(aq) + CN⁻(aq).

Qhov no solubility muab Sodium cyanide ib qho kev txav siab hauv cov dej hauv ib puag ncig, uas muaj ob qho tib si kev siv thiab kev cuam tshuam ib puag ncig. Piv txwv li, nyob rau hauv kub mining, lub soluble xwm ntawm NaCN enables nws tsim complexes nrog kub ions, yooj yim rau extracting kub los ntawm ore. Txawm li cas los xij, nws kuj txhais tau tias yog tias tsis muaj kev tswj hwm zoo, Sodium Cyanide tuaj yeem kis kab mob hauv dej tau yooj yim.

Hais txog lub cev muaj zog, sodium cyanide Nws muaj qhov kub kub ntawm 563.7 ° C thiab qhov kub ntawm 1496 ° C. Cov ntsiab lus siab melting thiab boiling no yog cov yam ntxwv ntawm ionic tebchaw, uas yuav tsum tau ib tug tseem ceeb npaum li cas ntawm lub zog los rhuav lub zog ionic bonds tuav lub ions ua ke.

Lwm yam khoom tseem ceeb ntawm sodium cyanide yog nws cov reactivity nrog acids. Thaum sodium cyanide los rau hauv kev sib cuag nrog cov kua qaub, nws sai sai reacts tsim hydrogen cyanide (HCN), ib tug heev toxic thiab volatile roj. Cov tshuaj tiv thaiv nrog cov kua qaub muaj zog, xws li hydrochloric acid (HCl), tuaj yeem sau tau: NaCN + HCl → NaCl + HCN↑. Cov tshuaj tiv thaiv no qhia txog qhov txaus ntshai heev cuam tshuam nrog sodium cyanide, vim tias cov kua qaub me me tuaj yeem ua rau muaj kev tso tawm cov pa roj hydrogen cyanide.

Reaction Mechanisms ntawm Sodium Cyanide

Ib qho zoo tshaj plaws-paub cov tshuaj tiv thaiv mechanisms uas muaj sodium cyanide yog nws siv nyob rau hauv cov hlau complexation, tshwj xeeb tshaj yog nyob rau hauv extraction ntawm precious hlau xws li kub thiab nyiaj. Cov txheej txheem hu ua cyanidation. Nyob rau hauv lub xub ntiag ntawm oxygen thiab dej, sodium cyanide reacts nrog kub nyob rau hauv lub ore los ua ib tug soluble kub - cyanide complex. Tag nrho cov tshuaj tiv thaiv rau leaching ntawm kub tuaj yeem sawv cev li: 4Au + 8NaCN + O₂ + 2H₂O → 4Na[Au(CN)₂] + 4NaOH.

Lub tshuab pib nrog oxidation ntawm kub los ntawm oxygen nyob rau hauv lub xub ntiag ntawm cyanide ions. Cov cyanide ions tom qab ntawd khi rau oxidized kub ions, tsim kom ruaj khov, dej - soluble dicyanoaurate(I) complex [Au(CN)₂]⁻. Cov tshuaj tiv thaiv complexion no zoo solubilizes kub, tso cai rau nws cais tawm ntawm cov ore matrix. Cov kauj ruam tom ntej no suav nrog kev rov qab kub los ntawm kev daws los ntawm ntau txoj hauv kev, xws li nag lossis daus nrog zinc lossis electrolysis.

Sodium cyanide kuj koom nrog hauv kev hloov pauv nucleophilic. Lub cyanide anion (CN⁻) yog ib qho muaj zog nucleophile vim muaj ib khub ntawm electrons ntawm cov pa roj carbon atom. Nyob rau hauv cov organic chemistry, piv txwv li, nws tuaj yeem hnov ​​​​mob nrog alkyl halides (R - X, qhov twg X yog halogen) hauv cov tshuaj SN₂ (bimolecular nucleophilic hloov pauv) cov tshuaj tiv thaiv. Cov txheej txheem tshuaj tiv thaiv dav dav yog: R - X + NaCN → R - CN + NaX. Hauv cov tshuaj tiv thaiv no, cov cyanide anion tawm tsam cov pa roj carbon atom txuas rau halogen los ntawm sab nraub qaum, tshem tawm cov halogen atom thiab tsim cov pa roj carbon tshiab - carbon daim ntawv cog lus hauv cov khoom nitrile (R - CN). Cov tshuaj tiv thaiv no yog qhov tseem ceeb hauv kev sib txuas ntawm ntau yam organic tebchaw, suav nrog cov tshuaj thiab tshuaj zoo.

Tsis tas li ntawd, sodium cyanide tuaj yeem ua rau hydrolysis hauv dej. Lub cyanide anion reacts nrog dej molecules los tsim hydrogen cyanide thiab hydroxide ions. Cov tshuaj tiv thaiv hydrolysis yog raws li nram no: CN⁻ + H₂O ⇌ HCN + OH⁻. Cov tshuaj tiv thaiv no yog thim rov qab thiab cuam tshuam los ntawm cov khoom xws li pH. Hauv cov kev daws teeb meem yooj yim, qhov sib npaug hloov mus rau cov reactants, suppressing tsim hydrogen cyanide. Txawm li cas los xij, nyob rau hauv cov kua qaub lossis nruab nrab, qhov tsim ntawm HCN yog qhov zoo dua, uas rov hais dua qhov xav tau kev tswj pH kom zoo thaum tuav cov tshuaj sodium cyanide.

Kev nyab xeeb thiab kev xav txog ib puag ncig

Muab nws cov xwm txheej muaj kuab lom heev, cov txheej txheem kev nyab xeeb yuav tsum tau ua raws li thaum tuav sodium cyanide. Cov neeg ua haujlwm koom nrog hauv kev tsim khoom, kev thauj mus los, lossis kev siv yuav tsum tau nruab nrog cov cuab yeej tiv thaiv tus kheej tsim nyog (PPE), suav nrog hnab looj tes, qhov ncauj qhov ntswg, thiab khaub ncaws tiv thaiv. Nyob rau hauv cov ntaub ntawv ntawm spills los yog leaks, tam sim ntawd tswj thiab neutralization ntsuas yog ib qho tseem ceeb. Feem ntau, sodium cyanide tuaj yeem ua rau nruab nrab los ntawm kev ua haujlwm nrog cov tshuaj oxidizing muaj zog, xws li cov tshuaj hypochlorite, uas hloov cov cyanide ions mus rau hauv cov khoom tsis muaj tshuaj lom.

Los ntawm ib puag ncig kev xav, kev tso tawm ntawm sodium cyanide mus rau hauv ib puag ncig tuaj yeem ua rau muaj kev cuam tshuam loj heev. Raws li tau hais ua ntej, nws cov dej solubility hauv dej tso cai rau nws kom paug cov dej hauv lub cev, ua rau muaj kev hem thawj rau cov dej hauv dej. Tsis tas li ntawd, kev tsim cov roj hydrogen cyanide tuaj yeem cuam tshuam rau huab cua zoo nyob ib puag ncig ntawm qhov nchuav. Yog li ntawd, kev lag luam uas siv sodium cyanide yuav tsum tau siv cov txheej txheem tswj cov khib nyiab thiab kev kho mob kom txo tau nws cov kev cuam tshuam ib puag ncig.

Hauv kev xaus, sodium cyanide yog qhov sib xyaw nrog cov khoom siv tshuaj lom neeg thiab muaj ntau hom tshuaj tiv thaiv. Thaum nws ua lub luag haujlwm tseem ceeb hauv ntau cov txheej txheem kev lag luam, nws cov tshuaj lom neeg tsis zoo thiab muaj peev xwm ua rau muaj kev phom sij rau ib puag ncig xav tau ceev faj thiab tswj xyuas. Kev tshawb fawb txuas ntxiv thiab txhim kho cov kev nyab xeeb thiab kev kho kom zoo dua rau sodium cyanide - cov khib nyiab cuam tshuam yog qhov tseem ceeb rau kev lag luam kev lag luam.