Waikawa

pūhui organic matū, i te iti rawa kia kotahi rōpū carboxyl i roto i tona hanganga nei rāpoi ngota (hāngai reira carbonyl - rōpū mahi o aldehydes me ketones, me hydroxyl - waipiro rōpū mahi) riro ingoa noa - waikawa. Tātai taea te māngai ratou rite R-COOH, te wahi R ko te rōpū mahi monovalent pūwaro. Tetahi waikawa, i roto i te rerekē ki te nuinga o ngā waikawa pararopi, ngoikore, me te incompletely dissociated ki katote.

Ka rite ki nga tauira māmā e formic (mewaro) waikawa H-COOH. E pā ana te ingoa ki te hītori o te tuatahi o tona taenga i 1670 o popokorua whero English taiao John Ray. Ka te waikawa he rōpū carboxyl rua, neke atu rānei e huaina dibasic (dicarboxylic), tribasic (tricarboxylic ranei), me te pera i runga i. Ko te tauira māmā he waikawa oxalic me tona C2H2O4 tātai, i roto i te rāpoi ngota e kei ngā rōpū carboxyl rua. Ka rite ki taea shestiosnovnoy arahi mellitic (geksakarbonovuyu) waikawa, tona C12H6O12 tātai. Kei roto i te rāpoi ngota e whakakapia e ono ngā rōpū carboxyl i roto i te ngota hauwai benzene mowhiti.

waikawa Organic te tikanga i kitea i roto i te natura. Hei tauira, i roto waikawa geksakarbonovaya i roto i te kohatu honi kitea i roto i lignites).

He maha pūhui tūturu nui i roto i tenei piha. Ko ētahi o ēnei citric waikawa C6H8O7 (tohu e rave rahi tāpiritanga kai E330-E333), i whiwhi tuatahi i te wai rēmana kaiota i roto i 1784 i te rongoā Swedish K. Scheele. Tātariki waikawa C4H6O6 ko te tāpiri kai E334). Kei te whānui tohaina tēnei waikawa i roto i te natura. Kei te roto te reira i roto i te wai hou o hua maha.

Ki te whakaaro tatou tetahi raupapa huirua o ngā pūhui matū waro, i roto i reira i reira he huringa auau i roto i ngā āhuatanga ki te whakanui ake i taimaha rāpoi. Ko te āhuatanga o ia pūhui whakawhirinaki i runga i te hanganga o nga rāpoi ngota, e ko, i roto i te tikanga maha tautuhi ratou poinanahatanga waikawa. Ko te māngai tuatahi o te raupapa huirua i hanga i te waikawa formic, tae atu ahetiki me propionic, e pā ana ki te wai. E āhuatanga ratou e te kakara mangeo me he ngāwari wairewa i roto i te wai. Ko te māngai teitei he totoka e kore e e memeha i roto i te wai.

āhuatanga matū o ngā waikawa e te nuinga whakaritea e te mana o te rōpū carbonyl ki te rōpū hydroxyl. Na reira, i enei pūhui, i roto i te rerekē ki te waiwaihā, te whai i te pūāhua waikawa korerotia.

Hei tauira, i roto i wairewa waiwai, kia dissociate ratou ki katote, e te akapapu e te tae wai i muri i te tāpiri tohu waikawa whero. fokotu'u tenei te aroaro o tīhiko hauwai. Ko, he waikawa te reo o ratou wairewa waiwai (pH iti iho i te 7).

A, no te pāhekoheko ki konganuku turanga nehenehe o hanga tai waikawa ranei: 2CH3-COOH + Mg → (CH3-tumutumu) 2Mg + H2 ↑.

tomo waikawa Organic ano ki tauhohe matū ki pākawa waro, displacing waikawa carbonic: 2CH3-COOH + MgCO3 → (CH3-tumutumu) 2Mg + H2O + CO2 ↑.

Ratou noa huru ki haukini ki te hanga i tai: CH3-COOH + NH3 → CH3-COONH4.

E whakareitia ake ana te āhuatanga waikawa ina e kitea i roto i te tuwhena ki te substituent pānga kino inductive waikawa organic. Hei tauira, te mahi o te māota i roto i te waikawa ahetiki i āta whakakapi kotahi ngota hauwai o ngota māota me te fariiraa i te waikawa chloroacetic, waikawa dichloroacetic, me te waikawa ka trichloroacetic, i reira te mea he hua koi i roto i o ratou āhuatanga waikawa.

Ka taea te whiwhi i tetahi waikawa i roto i te maha ngā huarahi. Ko te tino noa ko te tikanga, e hāngai ana nei i runga i te tauhohe o te piti hāora. Ka rite ki te tiaki tuatahi o te matū hohe waiwaihā aldehydes ranei. Ko tētahi atu tikanga o te whakaputa ngā waikawa organic ko te tauhohenga wai o nitriles e rerengia ana e te para ratou ki waikawa kohuke diluted.