He aha ka dissociation o ka wai?

A mau hihia o ka dissociation (palaho kaʻina nui (particles) o ka mea - hakakino Ion paha radicals - i liʻiliʻi (particles)) mea he electrolytic dissociation, ai ka'ākilikai lātoma ike electrolyte ma ka pāʻoihana (ma ka hopena o na nā lātoma o ka Polar'ūheheʻe) e wawahi mai i na mea i papa (particles): cations a me anions. Kēia wehewehe i ka hiki o ka electrolyte pāʻoihana e hoʻomaka uila.

Ua hoʻoholo ihola e kaʻana like i nā electrolytes i loko o nā pūʻulu: nawaliwali a me ka ikaika. Wai pili i ka nawaliwali electrolytes, ka dissociation o ka wai wehewehe aku ma ka mea uuku nui o dissociated nā lātoma, no ka mea, ua lawa ka hoʻopale a me kaʻaneʻane ole dissociate i loko o Ion. Pure (maemae) ka wai poorly e lawelawe uilaʻikena. O ke kumu ho i ka Nine Inch 'ano o ka lātoma ia iho, ka wā ikaika polarized hydrogen nā'ātomaʻoe i loko o ka lolouila wahī kŘpa a uuku o oxygen'Ātoma i ua negatively polarized.

Ka ikaika a me ka nawaliwali o ka electrolyte ua wehewehe aku ma keʻano o ke dissociation (hōʻike ma α, ua nui ua pinepine i olelo ia me ka% o ka 0 a hiki i 100, a ma ka hapa iki o ka pa alima mai 0 a hiki i 1) - ka hiki e disintegrate i loko o Ion, a laila lākiō o ka helu o ka hakina (particles) i waena o na (particles) e'opi. Waiwai e like meʻakika a me kumu paʻakai ma ka hana o ka Polar wai nā lātoma dissociate i loko o Ion loa. Ke dissociation o ka wai nā lātoma H2O hahai ma disintegration i loko o ka proton H + a hydroxyl pae OH-. Inā dissociation o ka electrolyte makana i loko o ka palapala o ka helu kaulike: M = K ++ A-, laila ka wai dissociation hiki ke hoikeia ma ka helu kaulike: OH N2O↔N ++, a me ka helu kaulike ma i ka hōʻailona i ko degere o ka wai dissociation hiki ke poe i loko o nā 'ano apau loa (ma ka kūpono lehulehu o protons a hydroxyl pūʻulu ka kūpono lehulehu): α = [H +] / [H2O] a α = [OH -] / [H2O]. Mai ka huina α ua loli ana ma ka Nine Inch ano o ka hui, akā, i ka pāʻoihana lehulehu a me ka wela ole wale, ka mea, me ke ano mua, e olelo e pili ana i ka mea'ē aʻe (ka mana) ke degere o ka dissociation.

Propensity nā lātoma nawaliwali electrolytes, a me ka wai, dissociate i loko o Ion pili kēia wehewehe aku ma ka dissociation a eia i (mau hihia i ka equilibrium ikaika), i hiki ke koho i Kd. No ka ho omaulia i kēia nui, i ke kānāwai o ka nuipa a hana, i ka haʻina o ka lākiō ma waena o nā nā paʻi hua i loaa mai, mai ka wahi ho pono hana. An electrolytic dissociation o ka wai - he decomposition e hoʻomaka ana i ka wai i loko o nā lātoma hydrogen protons a me hydroxyl pae, nae ka dissociation ikaika ua hoikeia ma ka helu kaulike: Kd = [H +] • [OH -] / [H2O]. Kēia nui o ka wai, he ikaika a me ka hilinaʻi nui wale ma luna o ka wela, i ka wela o ka 25C, Kd = 1,86 • 10-16.

Ike i ka molar nui o ka wai (18 nā huna / kameleona), a me ka malama ole i ka lehulehu o dissociated nā lātoma, a lawe i ka nuipa a 1 dm3 o ka wai no 1000 g., Hiki e huli i ka lehulehu o undissociated nā lātoma ma 1 dm3 o ka wai [H2O] = 1000 / 18.0153 = 55.51 Mol / dm3. A laila, mai ka helu kaulike o ka dissociation a eia i hiki ke loaʻa huahana lehulehu o protons a me hydroxyl pūʻulu. [H +] • [OH -] = 1,86 • 10-16 • 55,51 = 1 • 10-14. I ka extracting ka huinahalike kumu o ka kūpono waiwai loaa lehulehu o protons (hydrogen Ion), a hoʻoholo i kaʻakika o ka pāʻoihana a me ka lehulehu o hydroxyl pūʻulu i keia i: [H +] = [OH -] = 1 • 10-7.

Akā, ma ka aoao maoli i ka maemae wai hakuʻole no ka mea, o ka alo ma loko o nā mea hoʻoheheʻe kinoea a me ka wai mea hoʻohaumia ma nā 'ona (i ka mea wai - keia pāʻoihana likeʻole electrolytes), no laila, i ka lehulehu o ka hydrogen ma 25 ° C ka lehulehu o protons a hydroxyl pūʻulu mea okoa, mai aiee o 1 • 10-7. Ia mea, o kaʻakika o ka wai ma muli o ka hanana oʻaʻole wale nō i ke kaʻina hana e like me ka dissociation o ka wai. Ke hydrogen inideka o ka hopena maikaʻi Olelo Kikeke Ma o ka hydrogen ion lehulehu (pH), ka mea, ua wahahee no ka loiloi 'ana i kaʻakika a'ākilikai paha o ka wai a me ka koʻana koko pāʻoihana, e like me ka helu me ka hopena maikaʻi' mana hoʻohana pilikia. No ka maemae wai pH 7, akā, me he maemae ka wai ole mea, a me ka dissociation o ka wai kahe ana a me ka'opi o nā mea hoʻoheheʻe electrolytes, ka pH cia i e emi ma mua paha ka nui o 7, a laila no wai, kokoke ≠ pH 7.