Ajụjụ Ihe Nlereanya Mkparịta ụka gbasara Mkpụrụ ndụ Electrochemical: Ịghọta Isi Ihe Ndị Dị Mkpa nke Electrochemistry Site na Ajụjụ Ihe Nlereanya
Electrochemistry bụ ngalaba kemistri nke na-amụ mmekọrịta dị n'etiti mmeghachi omume kemịkalụ na ọkụ eletrik. Na electrochemistry, anyị na-ekwukarị ụdị mkpụrụ ndụ abụọ bụ isi: mkpụrụ ndụ galvanic (ma ọ bụ voltaic) na mkpụrụ ndụ electrolytic. Ụdị mkpụrụ ndụ abụọ a na-eji mmeghachi omume redox emepụta ma ọ bụ jiri ọkụ eletrik.
N'isiokwu a, anyị ga-atụle ụfọdụ ihe atụ nke mkpụrụ ndụ electrochemical ga-enyere anyị aka ịghọta echiche a nke ọma.
1. Ajụjụ: Mkpụrụ ndụ Galvanic
Dịka ọmụmaatụ, ka anyị were sel galvanic nke nwere elektrọd zinc (Zn) nke a gbanyere n'ime mmiri ZnSO₄ na elektrọd ọla kọpa (Cu) nke a gbanyere n'ime mmiri CuSO₄. Dee mmeghachi omume ndị na-eme na elektrọd ọ bụla, yana mmeghachi omume zuru oke na sel galvanic a.
Azịza:
1. Mmeghachi omume na elektrọd zinc (anode, oxidation):
Mmeghachi omume: \( Zn(s) \rightarrow Zn^{2+}(aq) + 2e^- \)
N'ebe a, a na-eme ka zinc ghọọ ion zinc (Zn²⁺) ma wepụta elektrọn abụọ.
2. Mmeghachi omume na elektrọd ọla kọpa (katode, mbelata):
Mmeghachi omume: (Cu^{2+}(aq) + 2e^- \rightarrow Cu(s) \)
N'ebe a, ion ọla kọpa (Cu²⁺) na-anabata elektrọn abụọ ma a na-ebelata ha ka ha bụrụ ọla kọpa siri ike (Cu).
3. Mmeghachi omume zuru oke na mkpụrụ ndụ galvanic:
Jikọta mmeghachi omume ọkara abụọ a iji nweta mmeghachi omume zuru oke:
\( Zn(s) + Cu^{2+}(aq) \rightarrow Zn^{2+}(aq) + Cu(s) \)
N'ozuzu, enwere ike ikwubi na n'ime mkpụrụ ndụ galvanic, a na-eji mmeghachi omume redox eme ihe n'enweghị ihe mgbochi iji mepụta ọkụ eletrik.
2. Ajụjụ: Ike Cell
Ebe ọ bụ na e nwere ike ibelata ọkwa Zn²⁺/Zn = -0,76 V na Cu²⁺/Cu = +0,34 V. Gbakọọ ikike sel nke sel galvanic a tụlere na mbụ.
Azịza:
Enwere ike ịgbakọ ike mkpụrụ ndụ (E°_cell) site na iji usoro nhazi:
\[
E°_{cell} = E°_{cathode} – E°_{anode}
\]
Ebe:
– Katode bụ elektrọd ebe mbelata na-eme (Cu²⁺/Cu na E° = +0.34 V)
– Anode bụ elektrọd ebe oxidation na-eme (Zn²⁺/Zn na E° = -0.76 V)
\[
E°_{sel} = 0.34\, V – (-0.76\, V) = 0.34\, V + 0.76\, V = 1.10\, V
\]
Ya mere, ikike sel nke sel galvanic bụ 1,10 V.
3. Ajụjụ: Mkpụrụ ndụ Electrolytic
N'ime sel electrolytic, a na-akwadebe mmiri sodium chloride (NaCl) n'ime sel electrolytic yana elektrọd na-anaghị arụ ọrụ. Dee mmeghachi omume ndị na-eme na elektrọd ọ bụla.
Azịza:
N'ime sel electrolytic, a na-eji ọkụ eletrik akwọ ihe na-anaghị eme ozugbo. N'ime sel electrolytic nwere mmiri NaCl, anyị nwere:
1. Mmeghachi omume na kathode (mbelata):
\[
2H_2O(l) + 2e^- \arrow H_2(g) + 2OH^-(aq)
\]
N'ọtụtụ mmiri NaCl a gwakọtara agwakọta, a ga-ebelata mmiri tupu sodium n'ihi na ike mbelata mmiri dị mma karịa sodium (-2.71 V).
2. Mmeghachi omume na anode (oxidation):
\[
2Cl^-(aq) \arrow Cl_2(g) + 2e^-
\]
Na anode, a na-eme ka ion chloride dị na gas chlorine.
3. Mmeghachi omume zuru oke:
Jikọta mmeghachi omume na cathode na anode maka mmeghachi omume zuru oke:
\[
2H_2O(l) + 2Cl^-(aq) \rightarrow H_2(g) + Cl_2(g) + 2OH^-(aq)
\]
N'ime electrolysis mmiri nnu a, a na-emepụta gas hydrogen na gas chlorine yana ngwọta isi (NaOH) n'ihi mmekọrịta nke ion dị na ngwọta ahụ.
4. Ajụjụ: Iwu Faraday nke Electrolysis
Ole gram ọla kọpa ka a na-esi na ngwọta CuSO₄ apụta ma ọ bụrụ na a na-agafe mmiri ọkụ ruo ụbọchị abụọ?
Azịza:
Iwu Faraday kwuru na ọnụọgụ ihe e tinyere na electrode n'oge electrolysis bụ nha nhata na ọnụọgụ ọkụ eletrik gafere na ya. Enwere ike ịgbakọ oke nke ihe (m) site na iji usoro nha:
\[
m = \frac{M \cdot Q}{n \cdot F}
\]
Ebe:
– \(m\) bụ oke nke ihe e tinyere n'ime ya
– \(M\) bụ oke molar nke ihe ahụ (maka Cu, M = 63.5 g/mol)
– \(Q\) bụ ọnụọgụ chajị eletriki (na coulombs, agbakọrọ dị ka \(Q = n \cdot F\), ebe n bụ ọnụọgụ nke faradays)
– \(n\) bụ ọnụọgụgụ nke mole nke elektrọn ndị metụtara na mmeghachi omume (maka Cu²⁺/Cu, n = 2)
– \(F\) bụ ihe na-agbanweghi agbanwe nke Faraday (96500 C/mol)
Na ọkụ eletrik abụọ nke ụbọchị:
\[
m = \frac{63.5\, g/mol \cdot 2 \cdot 96500\, C}{2 \cdot 96500\, C/mol}
\]
Mee ka usoro ahụ dị mfe:
\[
m = 63.5\, g
\]
Nsonaazụ ya bụ na e tinyere gram 63.5 nke ọla kọpa site na electrolysis a.
Mmechi
Ịghọta mkpụrụ ndụ electrochemical chọrọ ihe ọmụma gbasara mmeghachi omume redox, mgbakọ na mwepụ nke mkpụrụ ndụ, na stoichiometry electrochemical. Ịghọta nsogbu ihe atụ dịka nke dị n'elu na-enyere aka n'ịkọwapụta echiche ndị bụ isi na ojiji ha n'ụdị mkpụrụ ndụ electrochemical dị iche iche. N'ikpeazụ, gaa n'ihu na-eme ihe na nsogbu dị iche iche iji mee ka nghọta a dịkwuo omimi, karịsịa maka ma ojiji echiche na nke bara uru n'ọtụtụ ngalaba sayensị na ụlọ ọrụ.
