Te Mārama ki te Ira Rewa me te Ira Kohua
I roto i te matū me te ahupūngao, he mea nui te mārama ki ngā panonitanga o te āhua o te matū hei whakamārama i ngā āhuatanga o ia rā, mai i te rewa o te hukapapa ki te wai kohua. E rua ngā ariā matua e kōrerohia pinepinetia ana i roto i te kaupapa o ngā panonitanga o te āhua ko te ira rewa me te ira kohua. He hononga tata ēnei e rua ki te pāmahana motuhake e pāngia ai te matū e te panonitanga āhua, engari he whakamāramatanga motuhake, he āhuatanga awe, me te whakamahinga o ia mea. Ka matapakihia e tēnei tuhinga te tikanga o te ira rewa me te ira kohua, ō rāua rerekētanga, ngā āhuatanga awe, me ngā tauira o tā rāua whakamahinga i roto i te oranga o ia rā.
Te Mārama ki te Ira Rewa
Ko te ira rewa ko te pāmahana e huri ai te totoka hei wai i te pēhanga motuhake (ko te tikanga he 1 te hau). I tēnei pāmahana, ka whiwhi ngā matūriki e hanga ana i te totoka i te kaha wera e ranea ana hei wikitoria i ngā kaha kukume i waenganui i a rātou, ka hinga te hanganga totoka, ka huri hei wai.
Hei tauira, ko te hukapapa (wai totoka) he tata ki te 0°C te ira rewa i te 1 atm o te pēhanga. Ina werahia te hukapapa, ā, ka tae ki te 0°C, ka tīmata te rewa. He mea nui kia mārama ko te pāmahana o te ranunga hukapapa me te wai e kore e piki tonu ahakoa te whakamahana, nā te mea ka whakamahia te kaha wera hei whakarerekē i te āhua, ehara i te mea hei whakaara ake i te pāmahana.
He maha ngā wā ka whakamahia te ira rewa hei āhuatanga ā-tinana o tētahi matū. He pūmau, he koi hoki te ira rewa o ngā matū parakore, he rerekē ki ngā ranunga, e rewa ana i runga i tētahi awhe pāmahana kua whakaritea.
Te Whakamāramatanga o te Ira Kohua
Ko te pāmahana koropupū ko te pāmahana e huri ai te wai hei hau (kohu) puta noa i te wai, ehara i te mea i te mata anake, i raro i tētahi pēhanga kua whakaritea. Ko te āhuatanga tino nui i te pāmahana koropupū ko te ōrite o te pēhanga kohu o te wai ki te pēhanga o waho (hei tauira, te pēhanga hauātea). I tēnei wā, ka taea e ngā mirumiru kohu te hanga i roto i te wai ka piki ake ki te mata—koinei te mea e kiia ana he koropupū.
Ko te tauira tino kitea ko te wai, he 100°C te pāmahana koropupū i te pēhanga 1 atm. Ina werahia te wai ki te 100°C, ka tīmata te koropupū. Pērā i te pāmahana rewa, i te mea e koropupū ana te wai i te pēhanga pumau, ka noho tonu tōna pāmahana ahakoa kei te haere tonu te whakamahana, nā te mea ka whakamahia te pūngao wera hei huri i te wai hei hau (e kiia ana ko te wera huna o te mimiti).
He tohu nui anō hoki te ira kohua i roto i te tautuhi matū, te hoahoa tukanga ahumahi, me te whakatau i ngā tikanga whakamahana haumaru i roto i te taiwhanga.
Te rerekētanga i waenga i te Ira Rewa me te Ira Kohua
Ahakoa he rerekētanga āhuahanga ngā pāmahana e rua, he rerekētanga matua ngā ira rewa me ngā ira koropupū:
1. Te ahunga o te huringa āhua
– Te pūwāhi rewa: totoka → wai
– Te pūwāhi koropupū: wai → hau
2. Momo pūngao e whakamahia ana
– I te pūwāhi rewa, ka whakamahia te pūngao wera hei whakaiti i ngā hononga, i ngā kaha rānei i waenga i ngā matūriki i roto i te totoka kia taea ai e ngā matūriki te neke haere noa.
– I te pāmahana e koropupū ana, ka whakamahia te pūngao wera hei tuku i ngā matūriki mai i te āhua wai ki te hau, nō reira e hiahiatia ana he pūngao nui atu i te pūngao e rewa ana.
3. Ngā āhuatanga o te tukanga
– Ka puta te rewa i te rohe i waenganui i te totoka me te wai, kātahi ka horapa.
– Ko te āhua o te kohua he mirumiru kohu puta noa i te wai.
4. Te aro ki te pēhanga
– He nui te pānga o te pēhanga o waho ki te ira kohua.
– Ka pāngia hoki te ira rewa e te pēhanga, engari he iti ake te pānga mō te nuinga o ngā matū i te ira kohua.
Ngā Take e Pā Ana ki te Ira Rewa
He maha ngā āhuatanga ka pā ki te ira rewa o tētahi matū:
1. Momo me te kaha o ngā hononga i waenga i ngā matūriki
Ko ngā matū he kaha te kukume i waenga i ngā ngota ngota, he nui ake ngā ira rewa. Hei tauira, ko ngā matū ionic pērā i te konutai pūhaumāota (NaCl) he nui ake ngā ira rewa nā te mea he tino kaha ngā kaha hiko i waenga i ngā ion.
2. Hanganga karaihe
Ko te whakaritenga o ngā matūriki i roto i te tioata ka pā ki te ngāwari o te hinga o te hanganga ina werahia. Ko ngā tioata piripono, pumau, me nui ake te pūngao e hiahiatia ana kia rewa.
3. Te parakore o te matū
He mārama te ira rewa o ngā matū parakore. Ko ngā ranunga, ngā matū rānei kei roto ngā poke, he iti ake te ira rewa, ā, he whānui ake te awhe rewa. Ka whakamahia tēnei ariā i roto i ngā whakamātautau parakore taiwhanga.
4. Pēhanga
I roto i ētahi matū, ka taea e te pēhanga te whakanui ake, te whakaiti rānei i te ira rewa. Ko tētahi tauira rongonui ko te hukapapa: mā te whakanui ake i te pēhanga ka taea te whakaiti paku i te ira rewa, ka taea ai te rewa ngāwari ake o te hukapapa i ngā pēhanga teitei ake (he mātāpono e pā ana ki te nekehanga o ngā reti hukapapa i runga i te mata hukapapa).
Ngā āhuatanga e pā ana ki te ira koropupū
He nui ake te aro o ngā ira kohua ki ngā panonitanga o ngā āhuatanga i ngā ira rewa. Ko ētahi o ngā āhuatanga ko:
1. Pēhanga o waho
He mea nui tēnei. Ka iti ake te pēhanga o waho, ka iti ake te pūwāhi koropupū. I ngā teitei, ka iti ake te pēhanga o te āhuarangi, nō reira ka koropupū te wai i ngā pāmahana i raro iho i te 100°C. Nō reira, ka roa ake te tunu kai nā te mea he iti ake te pūwāhi koropupū mōrahi.
2. Ngā kaha ā-iwi
He teitei ngā ira kohua o ngā wai he kaha ngā hononga i waenga i ngā ngota ngota. Hei tauira, he hononga hauwai tō te wai, nō reira he teitei ake tōna ira kohua ki te whakatauritea ki ngā ngota ngota he rite te rahi, pērā i te hauwai whanariki.
3. Papatipu me te hanganga ngota
Ko ngā ngota nui ake, ngāwari ake te whakapororaru, he kaha ake te kaha o ngā kaha o Rānana e whakaatuhia ana e rātou, nō reira ka piki ake te pāmahana koropupū i te pikinga o te papatipu ngota (hei tauira, i roto i te raupapa alkane).
4. Te parakore o te matū
He rerekē ngā ira kohua o ngā ranunga, ā, he maha ngā wā ka whakaatuhia he awhe ira kohua. Ka whakamahia te whakamaroke hei wehewehe i ngā ranunga wai i runga i ngā rerekētanga o ngā ira kohua.
Ngā Tauira o ngā Pūwāhi Rewa me ngā Pūwāhi Kohua o ngā Matū Rerekē
Anei ētahi tauira noa (i te pēhanga 1 atm):
– Wai: te ira rewa 0°C; te ira kohua 100°C
– Waipiro (ethanol): te ira rewa tata ki te -114°C; te ira kohua tata ki te 78°C
– Rino: te ira rewa tata ki te 1538°C; te ira kohua tata ki te 2862°C
– Tote tēpu (NaCl): te ira rewa tata ki te 801°C; te ira kohua tata ki te 1413°C
E whakaatu ana ēnei tau he teitei ngā ira rewa me ngā ira kohua o ngā matū he kaha ngā hononga, engari he iti ngā ira kohua o ngā matū he ngoikore ngā kaha ā-iwi.
Te Whakamahinga o te Ira Rewa me te Ira Kohua i roto i te Ora
He tino whai hua te mārama ki ngā ira rewa me ngā ira koropupū i roto i ngā momo mara:
1. Ahumahi whakarewa
Ko te tukanga rewa whakarewa i roto i te hanga maitai, te whakarewa konumohe, me te whakarewa rino me whakahaere te pāmahana i runga i te ira rewa o te rauemi.
2. Ahumahi kai
Ko te kaupapa o te pūnga kohua te kaupapa o te tunu kai, te whakamātao, me te mimiti. Hei tauira, ko te mimiti i te hanga tote, i te miraka kukū rānei.
3. Taiwhanga me te whare rongoā
Ka whakamahia te ira rewa hei whakamātautau i te parakore o ngā pūhui totoka, ko te ira kohua ia he mea nui i roto i te whakahoromata mō te purenga whakarewa, te hanga pūhui rānei.
4. Hangarau me te miihini
Me mārama ki ngā huringa āhuahanga hei whakarite i te haumaru me te whai huatanga o ngā pūnaha whakamatao miihini, te hanga wahie, me te hoahoa taputapu whakamahana.
Whakamutunga
Ko te ira rewa te pāmahana e huri ai te totoka hei wai, ko te ira kohua ia ko te pāmahana e huri ai te wai hei hau ina rite te pēhanga o tōna kohu ki te pēhanga o waho. E pāngia ana ēnei e te āhua o te matū (te hononga me te hanganga matūriki), te parakore, me te pēhanga—ina koa mō te ira kohua. Mā te mārama ki ēnei ariā e rua ka āwhina i te whakamārama i ngā āhuatanga taiao, ā, he tūāpapa nui mō ngā tukanga ahumahi, te rangahau, me ngā mahi o ia rā. Mēnā ka mōhiotia pai, ehara i te mea he ariā ariā noa iho ngā ira rewa me te kohua, engari he taputapu mahi hoki mō te whakahaere me te whakamahi i ngā āhuatanga o te matū.
