Sodium Cyanide: Cov khoom siv tshuaj lom neeg thiab cov tshuaj tiv thaiv

Introduction

sodium cyanide (NaCN) yog ib qho tshuaj lom neeg uas muaj ob qho tib si kev lag luam thiab kev cuam tshuam kev nyab xeeb tseem ceeb vim nws qhov mob hnyav heev. To taub nws Tshuaj lom neeg thiab cov txheej txheem tshuaj tiv thaiv yog qhov tseem ceeb rau kev nyab xeeb, kev siv hauv tsev, thiab kev tiv thaiv ib puag ncig. Kab lus no yog tsim los muab cov ntsiab lus dav dav ntawm cov yam ntxwv ntawm cov tshuaj lom neeg thiab cov tshuaj tiv thaiv kab mob Sodium cyanide.

Chemical Properties ntawm Sodium Cyanide

lub cev Tsos

Sodium cyanide yog dawb, crystalline khoom nyob rau hauv chav tsev kub. Nws muaj cov qauv siv lead ua cubic thiab feem ntau tshwm me me, tsis muaj ntxhiab (thaum qhuav) granules lossis hmoov. Txawm li cas los xij, thaum nyob rau hauv kev sib cuag nrog dej los yog acids, nws muaj peev xwm tso tawm hydrogen cyanide gas, uas muaj ib tug txawv, ntsim almond tsw. Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias tsis yog txhua tus tuaj yeem tshawb pom tus ntxhiab tsw no, vim tias muaj peev xwm hnov ​​​​tsw nws yog kev txiav txim ntawm caj ces.

solubility

NaCN yog soluble hauv dej heev. Thaum nws yaj nyob rau hauv dej, nws dissociates rau hauv sodium ions (Na⁺) thiab cyanide ions (CN⁻) raws li nram no:

NaCN(s) H2O, Na+(aq) Na+(aq) + CN-(aq)

Qhov siab solubility hauv dej no ua rau nws muaj peev xwm ua rau muaj kev phom sij rau ib puag ncig vim nws tuaj yeem yooj yim kis cov dej. Nws kuj yog soluble nyob rau hauv ib co polar organic solvents xws li methanol thiab ethanol.

stability

Sodium cyanide ruaj khov nyob rau hauv cov xwm txheej ib txwm muaj. Txawm li cas los xij, nws rhiab heev rau cua sov, dej noo, thiab cov kua qaub. Thaum cua sov, nws tuaj yeem lwj, tso tawm cov pa roj hydrogen cyanide lom heev. Nyob rau hauv qhov muaj cov kua qaub, txawm tias cov kua qaub tsis muaj zog zoo li carbonic acid (tsim thaum carbon dioxide yaj hauv dej), cov tshuaj tiv thaiv hauv qab no tshwm sim:-NaCN + H2O + CO2 → NaHCO3 + HCN↑

Cov tshuaj tiv thaiv no qhia txog qhov tseem ceeb ntawm kev khaws cia Sodium Cyanide nyob rau hauv ib qho chaw qhuav, txias kom deb ntawm acidic tshuaj.

Reaction Mechanisms ntawm Sodium Cyanide

Cov tshuaj tiv thaiv nrog hlau

Sodium cyanide yog qhov zoo - paub txog nws lub peev xwm los tsim cov complexes nrog hlau. Ib qho ntawm cov kev siv ntau tshaj plaws yog nyob rau hauv kev rho tawm ntawm kub thiab nyiaj los ntawm lawv cov ore hauv kev lag luam mining. Nyob rau hauv lub xub ntiag ntawm oxygen thiab dej, sodium cyanide reacts nrog kub (Au) nyob rau hauv lub ore los ua ib tug soluble kub - cyanide complex. Tag nrho cov tshuaj tiv thaiv tuaj yeem sawv cev raws li:

4Au+8NaCN+O2+2H2O→4Na[Au(CN)2]+ 4NaOH

Nyob rau hauv cov tshuaj tiv thaiv no, cov cyanide ions koom tes nrog cov atoms kub, hloov cov kub insoluble nyob rau hauv cov ore mus rau hauv ib tug soluble complex uas yuav yooj yim cais los ntawm cov pob zeb seem thiab lwm yam impurities. Cov tshuaj tiv thaiv txheej txheem cuam tshuam nrog oxidation ntawm kub los ntawm oxygen, ua raws li cov complexation ntawm oxidized kub nrog cyanide ions.

Nucleophilic Reactions Reactions

Cyanide ions (CN⁻) yog cov muaj zog nucleophiles. Hauv cov organic chemistry, lawv tuaj yeem koom nrog kev hloov pauv nucleophilic. Piv txwv li, thaum ib qho alkyl halide (R - X, qhov twg R yog ib pawg alkyl thiab X yog halogen) reacts nrog sodium cyanide hauv cov kuab tshuaj aprotic xws li dimethyl sulfoxide (DMSO), cov tshuaj nram qab no tshwm sim:RX + NaCNR-CN + NaX

Lub cyanide ion tawm tsam cov pa roj carbon atom txuas rau halogen, tshem tawm cov halogen atom hauv kev hloov pauv. Cov tshuaj tiv thaiv no yog siv dav hauv kev sib txuas ntawm nitriles, uas yog cov intermediates tseem ceeb hauv kev tsim ntau yam organic tebchaw xws li carboxylic acids, amines, thiab heterocyclic compounds.

Cov tshuaj tiv thaiv dej (Hydrolysis)

Raws li tau hais ua ntej, sodium cyanide tuaj yeem cuam tshuam nrog dej hauv cov tshuaj tiv thaiv hydrolysis. Nyob rau hauv lub xub ntiag ntawm dej, lub cyanide ion tuaj yeem txais ib qho proton ntawm dej los tsim hydrogen cyanide thiab hydroxide ions:CN-(aq) + H2O(l) HCN (aq) + OH-(aq)

Cov tshuaj tiv thaiv hydrolysis no thim rov qab, thiab txoj haujlwm ntawm qhov sib npaug yog nyob ntawm yam xws li pH thiab kub. Hauv cov tshuaj acidic, qhov sib npaug hloov mus rau qhov tsim ntawm hydrogen cyanide gas, thaum nyob rau hauv cov kev daws teeb meem, cov cyanide ion tseem nyob hauv nws daim ntawv anionic.