He aha ka hopena Redox?
Pendahuluan
I ke ao o ke kemika, he nui nā kaʻina hana kūlohelohe a me nā hana hana i hana i kahi kuleana koʻikoʻi i ke ola o kēlā me kēia lā. ʻO kahi hanana kemika koʻikoʻi ka hopena redox. ʻO ka huaʻōlelo "redox" ke kū nei no ʻelua mau kaʻina hana like: ka hōʻemi a me ka oxidation. E wehewehe kikoʻī kēia ʻatikala i ke ʻano o ka hopena redox, pehea e hana ai, kona koʻikoʻi i ke ola o kēlā me kēia lā, a me kāna mau noi ākea.
Ka Wehewehena a me nā Kumu o nā Hana Redox
ʻO ka hopena redox kahi ʻano hopena kemika e pili ana i ka hoʻoili ʻana o nā electrons ma waena o ʻelua mau mea. Ma kēia kaʻina hana, nalowale kekahi mea i nā electrons (oxidation) a loaʻa i kekahi mea nā electrons (reduction). No laila, hana mau nā hopena redox; ʻaʻohe oxidation me ka ʻole o ka reduction, a ʻo ka hope.
ʻOkika
Ua wehewehe ʻia ka oxidation ʻo ia ka wehe ʻana o nā electrons mai kahi ʻātoma, ion, a i ʻole molekala. Ma kēia kaʻina hana, piʻi ka helu oxidation o ka mea e hana ʻia ana ka oxidation. No ka laʻana, ma ka hopena:
\[ \text{Zn} \rightarrow \text{Zn}^{2+} + 2e^- \]
Hoʻokuʻu ʻo Zinc (Zn) i ʻelua mau electrons a hana i ka oxidation.
Hoʻemi ʻana
ʻO ka hōʻemi ke kū'ē i ka oxidation. Ma kēia kaʻina hana, loaʻa i kahi ʻātoma, ion, a i ʻole molekala nā electrons, e hoʻemi ana i kona helu oxidation. No ka laʻana, ka hopena:
\[ \text{Cu}^{2+} + 2e^- \polokau \text{Cu} \]
ʻAe nā iona keleawe (Cu²⁺) i ʻelua mau electrons a hana i ka hōʻemi.
Nā mea hoʻomake a me nā mea hōʻemi
I loko o kahi hopena redox, ʻo ka mea e ʻae ana i nā electrons (e hana ana i ka hoʻemi ʻana) ua kapa ʻia ʻo ia ka oxidizing agent, ʻoiai ʻo ka mea e hāʻawi ana i nā electrons (e hana ana i ka oxidation) ua kapa ʻia ʻo ia ka reducing agent. No ka laʻana, i ka hopena ma waena o nā ion zinc a me ke keleawe:
\[ \kikokikona{Zn} + \kikokikona{Cu}^{2+} \rightarrow \kikokikona{Zn}^{2+} + \kikokikona{Cu} \]
Hana ʻo Zinc (Zn) ma ke ʻano he mea hoʻemi a hana nā ion keleawe (Cu²⁺) ma ke ʻano he mea hoʻomakeʻe.
Ke Kaʻina Hana o nā Hana Redox
Hana ʻia nā hopena redox ma o kekahi mau ʻanuʻu e pili ana i ka hoʻoili uila. Aia kekahi mau ala e nānā ai i nā loli i nā hopena redox, me ka helu ʻana i nā loli i ka helu oxidation a me ka nānā ʻana i ka hoʻoili uila.
Helu ʻokikene
ʻO ka helu oxidation kahi helu e hōʻike ana i ka hoʻouku kuhi ʻia o kahi ʻātoma i loko o kahi hui. Aia kekahi mau lula kumu no ka hoʻoholo ʻana i nā helu oxidation:
1. ʻO 0 ka helu oxidation o nā mea manuahi.
2. Loaʻa i nā ion monatomic kahi helu oxidation e like me ka hoʻopiʻi ionic.
3. ʻO ka maʻamau, he +1 ka helu oxidation o ka hydrogen, koe wale nō nā metal hydrides.
4. ʻO ka maʻamau, he -2 ka mokuʻāina oxidation o ka oxygen, koe wale nō i nā peroxides a i ʻole me ka fluorine.
5. ʻO ka huina o nā helu oxidation o nā ʻātoma āpau i loko o kahi molekala kūlike ʻole he 0, ʻoiai i loko o kahi ion polyatomic, ua like ka huina me ka uku o ka ion.
Nā Hana Kūlohelohe a me nā Hana Electrochemical
ʻO ka hopena redox kūlohelohe kahi hopena e hana ʻia me ka ʻole o ka hoʻohui ʻana o ka ikehu o waho. Hoʻohana pinepine ʻia kēia mau hopena i nā cell electrochemical, kahi e hoʻohana ʻia ai nā hopena redox e hana i ka uila. No ka laʻana, hoʻopuka kahi cell galvanic (cell voltaic) i kahi au uila mai kahi hopena kūlohelohe ma waena o ʻelua mau electrodes i loko o kahi hopena electrolyte.
Nā Hoʻohana o nā Reactions Redox
He nui nā noi o nā hopena redox ma nā ʻano like ʻole, me ka ʻoihana, ka biology, a me ke ola o kēlā me kēia lā.
ʻOihana
I ka ʻoihana, he kuleana koʻikoʻi nā hopena redox i ka hana ʻana i ka metala. No ka laʻana, ʻo ke kaʻina hana o ka unuhi ʻana i ka hao mai kāna ore e hoʻohana ana i ka hopena hōʻemi o ke kalapona me ka iron oxide:
\[ \kikokikona{Fe}_2\kikokikona{O}_3 + 3\kikokikona{C} \rightarrow 2\kikokikona{Fe} + 3\kikokikona{CO} \]
Eia kekahi, hoʻohana ʻia ke kaʻina hana electrolysis no ka hana ʻana i nā metala e like me ka alumini a me ka sodium.
ʻO ke olaola
I loko o nā pūnaewele ola, he mea koʻikoʻi nā hopena redox i ke kaulahao hanu pūnaewele. ʻO Mitochondria, i ʻike ʻia ʻo ia nā hale mana ikehu o ke kelepona, hoʻohana i nā hopena redox e hana i ka ATP (adenosine triphosphate), ke kumu ikehu mua no nā hopena biochemical he nui.
Ke ola o kēlā me kēia lā
Loaʻa ka oxidation a me ka hōʻemi ʻana i nā ʻano he nui o ke ola o kēlā me kēia lā, e like me:
– Ke kuni ʻana: ʻO ka hapa nui o nā kaʻina hana kuni he mau hopena redox e pili ana i ka oxidation o ka wahie e ka oxygen. No ka laʻana, ke kuni ʻana o ka methane:
\[ \kikokikona{CH}_4 + 2\kikokikona{O}_2 \rightarrow \kikokikona{CO}_2 + 2\kikokikona{H}_2\kikokikona{O} \]
- Photosynthesis: Hoʻohana nā mea kanu i nā hopena redox i ke kaʻina hana o ka photosynthesis e hoʻololi i ka wai a me ke kalapona dioxide i glucose a me ka oxygen.
– Nā Accumulators a me nā Pila: Hilinaʻi nā pila i nā hopena redox e hana i ka uila i hoʻohana ʻia no nā mea like ʻole.
Ka hopena
He mea nui nā hopena redox i ka kemika a he hopena koʻikoʻi ko lākou i nā wahi he nui o ke ola kanaka. Ma ka hoʻomaopopo ʻana i nā kumu o ka oxidation a me ka reduction a pehea e hoʻoili ʻia ai nā electrons, hiki iā mākou ke hoʻomaopopo maikaʻi i nā kaʻina hana kemika e kākoʻo ana i ka ʻenehana hou, ke olakino, a me ke kaiapuni. ʻO nā noi o nā hopena redox, mai ka ʻoihana a i ka biology a me nā pono o kēlā me kēia lā, e hōʻike ana i ke koʻikoʻi o kēia mau hanana i ko mākou ola. ʻO ka hoʻomaopopo ʻana i nā hopena redox ʻaʻole wale e kōkua iā mākou i ka ʻepekema a me ka ʻenehana akā hoʻonui pū i ko mākou ʻike i nā ʻano he nui o ke ao holoʻokoʻa a mākou e noho nei.
