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

Introduction

Sodium cyanide (NaCN) yog ib hom tshuaj lom neeg uas muaj ob qho tib si rau kev siv hauv kev lag luam thiab kev nyab xeeb vim nws muaj tshuaj lom heev. Kev nkag siab txog nws cov khoom siv tshuaj lom neeg thiab cov txheej txheem ua haujlwm yog qhov tseem ceeb rau kev tuav pov hwm kev nyab xeeb, kev siv hauv kev lag luam, thiab kev tiv thaiv ib puag ncig. Tsab xov xwm no lub hom phiaj yog los muab kev nkag siab dav dav txog cov yam ntxwv tshuaj lom neeg thiab cov txheej txheem ua haujlwm ntawm 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 heev 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 xws li Carbon ic acid (tsim thaum carbon dioxide yaj hauv dej), cov tshuaj tiv thaiv hauv qab no tshwm sim:- NaCN + H2O + CO2 → NaHCO3 + HCN↑

Qhov kev tshuaj tiv thaiv no qhia txog qhov tseem ceeb ntawm kev khaws cia Sodium Cyanide rau hauv qhov chaw qhuav, txias uas tsis muaj cov tshuaj acidic.

Reaction Mechanisms ntawm Sodium Cyanide

Cov tshuaj tiv thaiv nrog hlau

Sodium cyanide yog ib qho khoom siv uas paub zoo txog nws lub peev xwm los tsim cov khoom sib xyaw nrog cov hlau. Ib qho ntawm cov ntawv thov feem ntau yog kev rho tawm kub thiab nyiaj los ntawm lawv cov ores hauv kev lag luam mining. Thaum muaj oxygen thiab dej, sodium cyanide reacts nrog kub (Au) hauv cov ore los tsim cov kub soluble - cyanide complex. Qhov kev cuam tshuam tag nrho 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 nucleophiles muaj zog. Hauv cov organic chemistry, lawv tuaj yeem koom nrog cov tshuaj hloov pauv nucleophilic. Piv txwv li, thaum alkyl halide (R - X, qhov twg R yog pawg alkyl thiab X yog halogen) reacts nrog sodium cyanide hauv cov kuab tshuaj aprotic zoo li dimethyl sulfoxide (DMSO), cov tshuaj tiv thaiv hauv 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 lawm, sodium cyanide tuaj yeem ua rau dej sib xyaw ua ke hauv hydrolysis reaction. Thaum muaj dej, cov cyanide ion tuaj yeem txais cov proton los ntawm dej los tsim cov 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.