Ka ikaika o ka waikawa-kumu a me ka pH
ʻO nā waikawa a me nā kumu ʻelua mau manaʻo nui i ka kemika e pāʻani ana i kahi kuleana koʻikoʻi i nā ʻano hana kemika like ʻole a me nā kaʻina hana ola. ʻO ka hoʻomaopopo ʻana i ka ikaika o nā waikawa a me nā kumu, a me ko lākou ana ʻana, he mea nui ia ma nā ʻano hana hoʻokolohua a me nā noi o kēlā me kēia lā. E ʻimi kēia ʻatikala i ka ikaika o nā waikawa a me nā kumu, ke kumumanaʻo o ka pH, a pehea lākou e pili ai a hoʻopili ʻia.
Ka Wehewehena o nā ʻakika a me nā kumu
I nā huaʻōlelo maʻalahi, he mea hiki ke hāʻawi i nā iona hydrogen (H⁺) i loko o ka hopena, ʻoiai he mea hiki ke ʻae i kēia mau iona hydrogen ke kumu o ka wehewehe ʻana. Hoʻokumu ʻia kēia wehewehe ʻana ma ke kumumanaʻo Bronsted-Lowry. Ma ke ʻano ʻē aʻe, e like me ke kumumanaʻo Arrhenius, he mea hui ka waikawa e hana ana i nā iona hydronium (H₃O⁺) i loko o ka wai, a he mea hui ka kumu e hana ana i nā iona hydroxide (OH⁻) i loko o ka wai.
Ka ikaika o nā waikawa a me nā kumu
Ikaika ʻakika
ʻO ka ikaika o kahi waikawa e pili ana i kona hiki ke hoʻokuʻu i nā iona hydrogen (H⁺) i loko o ka hopena. Hoʻokaʻawale loa nā waikawa ikaika i ka wai, ʻo ia hoʻi, hoʻokuʻu ka hapa nui o nā molekole waikawa iā H⁺. ʻO nā hiʻohiʻona o nā waikawa ikaika ka waikawa hydrochloric (HCl), ka waikawa sulfuric (H₂SO₄), a me ka waikawa nitric (HNO₃).
I ka hoʻohālikelike ʻana, hoʻokaʻawale hapa wale nā waikawa nāwaliwali i loko o ka hopena. ʻO nā hiʻohiʻona o nā waikawa nāwaliwali e komo pū me ka waikawa acetic (CH₃COOH) a me ka waikawa carbonic (H₂CO₃). ʻO ke kekelē o ka hoʻokaʻawale ʻana o kahi waikawa nāwaliwali e hōʻike pinepine ʻia ma ke ʻano o ka waikawa dissociation constant (Ka).
Ikaika Kumu
E like me nā waikawa, hiki ke hoʻokaʻawale ʻia nā kumu ma ke ʻano he mau kumu ikaika a nāwaliwali paha. ʻO nā kumu ikaika nā mea e aneane piha i ka ionization i loko o ka hopena. ʻO nā hiʻohiʻona o nā kumu ikaika e komo pū me ka sodium hydroxide (NaOH) a me ka potassium hydroxide (KOH).
ʻO nā kumu nāwaliwali, ma ka ʻaoʻao ʻē aʻe, hoʻokahe hapa wale nō i loko o ka hopena. ʻO nā hiʻohiʻona o nā kumu nāwaliwali e komo pū me ka ammonia (NH₃). Ana ʻia hoʻi ka ikaika o kahi kumu ma ke ʻano o ka dissociation constant kumu (Kb).
Manaʻo pH
ʻO ka pH ke ana o ka acidity a i ʻole ka alkalinity o kahi hopena. He unahi logarithmic ia mai ka 0 a i ka 14. Ua wehewehe ʻia kēia unahi penei:
\[
\kikokikona{pH} = -\log[H⁺]
\]
ʻO [H⁺] ka nui o nā iona hydrogen i loko o ka hopena. Ua manaʻo ʻia he kū ʻole ka pH o 7 (e like me ka wai maʻemaʻe), he waikawa ka pH ma lalo o 7, a he kumu ka pH ma luna o 7.
Pilina ma waena o ka ikaika a me ka pH
Hoʻopilikia nui ka ikaika o kahi waikawa a i ʻole ke kumu i ka pH o kahi hopena. No nā waikawa ikaika, no ka mea ua hoʻokaʻawale loa lākou, hiki ke helu pololei ʻia ka pH mai ko lākou ʻano molar. No ka laʻana, he pH o kahi hopena 0.1 M HCl:
\[
\kikokikona{pH} = -\log[0.1] = 1
\]
No nā waikawa nāwaliwali, ʻaʻole i piha ke kekelē o ka dissociation, no laila ʻaʻole hiki ke helu pololei ʻia ka pH mai ka nui o ka molar mua. Akā, hoʻohana mākou i ka hoohalike Ka e hoʻoholo ai i ka nui o ka ion hydrogen ma ke kaulike.
Laʻana: No ka waikawa acetic (CH₃COOH) me Ka = 1.8 x 10⁻⁵, hiki iā mākou ke helu i ka pH o kahi hopena 0.1 M me ka hoʻohana ʻana i ka hoohalike:
\[
Ka = \frac{[H⁺][A⁻]}{[HA]}
\]
Ke manaʻo nei ʻo [H⁺] a me [A⁻] ʻo x a ʻo [HA] ≈ 0.1 – x. Mai ʻaneʻi, e hoʻoholo no x ʻo ia hoʻi ʻo [H⁺], a laila e helu i ka pH.
Nā Hoʻohana i ke Ola o kēlā me kēia Lā
ʻO ka hoʻomaopopo ʻana i ka ikaika o nā waikawa a me nā kumu a me ka pH he nui nā noi i ke ola o kēlā me kēia lā:
1. ʻOihana Meaʻai a me Mea Inu
He kuleana koʻikoʻi ko ka pH i ka hana ʻana i ka meaʻai a me ka mea inu. No ka laʻana, pono ka pH kūpono no ka hoʻoulu ʻana o ka pia a me ka waina. Hoʻohana ʻia nō hoʻi ia e mālama i ka maikaʻi a me ka palekana o nā huahana meaʻai.
2. Ke Kaulike o ke Ola Kino a me ke Kino
Pono ke kino kanaka i kahi pH paʻa ma o kāna mau ʻōnaehana like ʻole. ʻO ke koko kanaka, no ka laʻana, he pH ma kahi o 7.4. Hiki i nā loli liʻiliʻi i ka pH koko ke hoʻoulu i nā pilikia olakino koʻikoʻi.
3. Mahiʻai
ʻO ka lepo me ka pH kūpono ke kī i ka mahiʻai holomua. Hoʻopilikia ka pH lepo i ka loaʻa ʻana o nā meaʻai i nā mea kanu. No laila, hoʻoponopono pinepine nā mahiʻai i ka pH lepo ma ka hoʻohui ʻana i ka lime e hoʻokiʻekiʻe iā ia a i ʻole ka sulfur e hoʻohaʻahaʻa iā ia.
4. Ka Hoʻōla Wai
He mea nui ka pH o ka wai no ka maikaʻi o ka wai. Hiki i ka mālama ʻana i ka pH o ka wai ke hoʻopili i nā kumu like ʻole, me ka ʻono, ke kala, a me ka disinfection. Hoʻohui pinepine ʻia nā waikawa a i ʻole nā base i ka wai e hoʻokō ai i ka pH i makemake ʻia i ka wā o nā kaʻina hana mālama wai.
5. Ka Mana Hoʻohaumia
Nānā mau nā ʻoihana i ka pH o kā lākou wai hoʻoneoneo e hoʻokō i nā kūlana kaiapuni a hōʻemi i ka haumia. Ma mua o ka hoʻokuʻu ʻia ʻana o ka wai hoʻoneoneo i ke kaiapuni, hoʻopau pinepine ʻia ia ma ka hoʻohui ʻana i ka waikawa a i ʻole ke kumu e hoʻokokoke aku ai i ka pH i ka neutral.
Nā Kumu e Hoʻopilikia ana i ka Ikaika o nā Waikawa a me nā Kumu
Aia kekahi mau kumu e hoʻololi ai i ka ikaika o nā waikawa a me nā kumu, ʻo ia hoʻi:
1. ʻAno Molekala
He kuleana koʻikoʻi ko ke ʻano molekala i ka hoʻoholo ʻana i ka ikaika o kahi waikawa a i ʻole kumu. ʻO nā waikawa me nā pilina ikaika ma waena o nā ʻātoma hydrogen a me ka ʻātoma hoʻopaʻa e nāwaliwali pinepine no ka mea he paʻakikī iā lākou ke hoʻokuʻu i nā iona hydrogen. I ke ʻano ʻē, ʻo nā waikawa me nā pilina nāwaliwali e ikaika pinepine.
2. Ka Electronegativity
Pili maikaʻi ka electronegativity o nā ʻātoma hoʻopaʻa i ka ikaika o ka waikawa. ʻO nā ʻātoma me nā electronegativities kiʻekiʻe e huki pinepine i nā electrons hou aku, e maʻalahi ai iā lākou ke hoʻokuʻu i nā ion hydrogen.
3. Mea hoʻoheheʻe
Hoʻopilikia pū nā mea hoʻoheheʻe i ka ikaika o nā waikawa a me nā kumu. No ka laʻana, he mea hoʻoheheʻe maikaʻi loa ka wai no nā waikawa a me nā kumu ma muli o kona polarity kiʻekiʻe.
4. Hopena Hoʻokomo
ʻO ka hopena inductive o nā hui atomika like ʻole i loko o kahi molekala e hoʻopilikia pū i kona ikaika. ʻO nā hui electron-withdrawing (e like me nā halogens) i loko o kahi molekala e hoʻonui i ka acidity.
Ka hopena
ʻO ka ʻike o nā waikawa a me nā kumu, me ko lākou ikaika a me ka pH, he mea nui ia no ka hoʻomaopopo ʻana i nā hopena kemika he nui a me nā noi ma nā ʻano like ʻole. Hoʻoholo ʻia ka ikaika o nā waikawa a me nā kumu e ko lākou hiki ke hoʻokuʻu a ʻae paha i nā iona hydrogen, kahi e pili pono ana i ka pH o kahi hopena. He mea kōkua ka hoʻomaopopo ʻana i kēia ʻike ʻaʻole wale ma nā ʻano ʻepekema akā i ke ola o kēlā me kēia lā a me nā ʻoihana like ʻole. Hoʻomākaukau kēia ʻike i ke ala no nā noi ākea a kōkua i ka hoʻokō ʻana i nā ʻano hana kūpono ma nā ʻano hana like ʻole, mai ka ʻoihana meaʻai a hiki i ka mālama wai a me ke olakino. No laila, ʻo ka ʻike ʻana iā ia ke kī i ka holomua ʻenehana a me ka hoʻomaikaʻi ʻana i ke ʻano o ke ola.
