Dissociation ya metsi ke eng?

A sebetsana le nyeoe e itseng ea dissociation (bola thulaganyou e likaroloana kholoanyane ea taba - ions limolek'hule kapa radicals - ho likaroloana tse nyenyane tse) ke dissociation electrolytic, oo ka oona ho se nke lehlakore molek'hule tsebahalang electrolyte ka tharollo (by sephetho sa limolek'hule tsa solvent Polar) qhaqha ka likaroloana qosoa: cations le anions. Sena se hlalosa bokhoni ba ditharollo electrolyte ho khanna motlakase.

Ho etsa qeto ea ho abelana electrolyte tsohle ka lihlopha tse peli: ba fokolang le ho ba matla. Metsi le bolela electrolyte fokolang, le dissociation ya metsi tšoauoa ka e nyenyane ea limolek'hule dissociated, kaha ba na le ho lekaneng manganga le hoo e batlang e ha ho na dissociate ka ions. Bo hloekileng (makhethe) metsi hampe khanna motlakase hona joale. Sena ke ka ntlha ya go ho lik'hemik'hale mofuta wa molek'hule ka boeona, ha sebele polarized liathomo hydrogen li itsebisa ka enfelopo elektroniki fokolang oksijene athomo e hlonamisitsoe polarized.

matla le bofokoli ba electrolyte e tšoauoa ka tsela e itseng ea dissociation (o ile a bontša ka ho α, palo ena e atisa ho bontšoa ka% ya 0 ho 100, kapa likaroloana tsa ea unit trust tloha 0 ho 1) - le matla a ho oa putlama ka ions, i.e. karo-karolelano ea palo ea likaroloana robehileng har'a likaroloana ho putlama. Dintho tse kang acid e le setsi letsoai ke ketso ea polar limolek'hule metsi dissociate ka ions ka ho feletseng. The dissociation ea limolek'hule metsi H2O lateloa ke disintegration e be le proton H + kapa hydroxyl sehlopha OH-. Ha dissociation tsa electrolyte teng ka sebōpeho sa abel: M = K ++ A-, ka nako eo metsi a dissociation ka bontšoa ka ho abel: OH N2O↔N ++, le abel ke eo tekanyo hakantse tsa dissociation metsi ka emetsweng mefuta e 'meli (ka e sephetho le mahloriso tsa protons kapa lihlopha hydroxyl ea sephetho le mahloriso): α = [H +] / [H2O] kapa α = [OH -] / [H2O]. Ho tloha ka chelete e α a ameha feela ke mofuta lik'hemik'hale ea ho kompone, empa tharollo mahloriso kapa mocheso, ho tloaelehile ho bua ka bonahalang eka (inahanelang) tekanyo ea ho dissociation.

Sekamela limolek'hule electrolyte fokolang, ho akarelletsa le metsi, dissociate ka ions haholo tšoauoa ka e dissociation kamehla (nyeoe e 'ngoe e itseng ea equilibrium kamehla), e leng e ka khethoa e le Kd. Ho a bale boleng ena, molao oa boima bohato, e beha karo-karolelano pakeng tsa matšoele fumaneha thepa ho qala. E dissociation electrolytic ea metsi - ya li bole kapele 'qalang limolek'hule metsi protons hydrogen le hydroxyl sehlopha, leha ho le joalo le dissociation kamehla e bontšoa ka abel ho: Kd = [H +] • [OH -] / [H2O]. palo ena ea metsi ke kamehla le itšetlehile feela ka mocheso, ka mocheso oa 25C, Kd = 1,86 • 10-16.

Ho tseba batho ba bangata molare ea metsi (18 dikgerama / mole), 'me ho hlokomoloha ea mahloriso ea limolek'hule dissociated le ho le boima ba 1 dm3 tsa metsi ka 1000 g,, ka a bale mahloriso ea limolek'hule undissociated 1 dm3 ea metsi [H2O] = 1000 / 18.0153 = 55.51 Mol / dm3. Ka mor'a moo, ho tloha abel tsa dissociation kamehla ka fumanoa sehlahisoa mahloriso tsa protons le lihlopha hydroxyl: [H +] • [OH -] = 1,86 • 10-16 • 55,51 = 1 • 10-14. Ha ho tlhotla motso lisekoere tsa boleng fumana sephetho le mahloriso tsa protons (hydrogen ions), e leng qeto e acidity ea tharollo le mahloriso tsa lihlopha hydroxyl lekanang ho: [H +] = [OH -] = 1 • 10-7.

Empa lintho tsa tlhaho ho hloka sekoli joalo metsi ha a eo ka lebaka la ho ba teng ho eona ea likhase qhibiliha kapa silafatsoa metsi ke lintho tse ling tse (ka metsi hantle - ena tharollo electrolyte tse sa tšoaneng), e le hore ea mahloriso ea hydrogen ka 25 ° C ea mahloriso ea protons kapa lihlopha hydroxyl o fapane le melao ea boitšoaro ea 1 • 10-7. Ke hore, acidity ea metsi ka lebaka la ketsahalo e sa feela tšebetso e kang ea dissociation tsa metsi. Index hydrogen ke logarithm mpe tsa mahloriso Ion hydrogen (ph), ho e hlahiswa bakeng sa ho hlahloba le acidity kapa alkaline tsa metsi le tharollo ea metsi, e le linomoro le matla mpe sebelisa thata. Bakeng sa metsi e ba a hloekileng ph 7, empa metsi a ka tlhaho e hloekileng ke ho se joalo, le dissociation metsi phallang hammoho le ho putlama ha electrolyte tse ling qhibiliha, boleng ph ka 'na ba tlaase ho moo ho feta kapa a maholo ho feta 7, i.e. bakeng sa metsi, hoo e batlang e ≠ ph 7.