2\. B Electrorefining of copper | Complete and balance the electrode reactions ----------------------------- | -------------------------------------------- 16\. Dissociation of aq. copper sulphate | CuSO₄ ............... + ............... | H₂O ............... + ............... 17\. Reaction at cathode [pure thin sheet of Cu] | Cu²⁺ + ............... ............... [Cu deposited on thin sheet] 18\. Reaction at anode [impure block of active Cu] | Cu - ............... ............... [product nil - Cu²⁺ ions] Electrometallurgy of sodium | 19\. Dissociation of sodium chloride fused | NaCl ............... + ............... 20\. Reaction at cathode [inert - electrode] | Na¹⁺ + ............... ............... [product Na metal] 21\. Reaction at anode [inert - electrode] | Cl^1- - ............... ............... | Cl + Cl ............... [product Cl₂ gas] Electrometallurgy of aluminium | 22\. Dissociation of pure alumina| Al₂O₃ ............... + ............... 23\. Reaction at cathode [inert - electrode] | Al³⁺ + ............... ............... [product Al metal] 24\. Reaction at anode [inert - electrode] | O^2- - ............... ............... 3O₂ [product O₂ gas]

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2\. B Electrorefining of copper | Complete and balance the electrode reactions ----------------------------- | -------------------------------------------- 16\. Dissociation of aq. copper sulphate | CuSO₄ Cu²⁺ + SO₄^2- | H₂O H¹⁺ + OH^1- 17\. Reaction at cathode [pure thin sheet of Cu] | Cu²⁺ + 2e^- Cu [Cu deposited on thin sheet] 18\. Reaction at anode [impure block of active Cu] | Cu - 2e^- Cu²⁺ [product nil - Cu²⁺ ions] Electrometallurgy of sodium | 19\. Dissociation of sodium chloride fused | NaCl Na¹⁺ + Cl^1- 20\. Reaction at cathode [inert - electrode] | Na¹⁺ + 1e^- Na [product Na metal] 21\. Reaction at anode [inert - electrode] | Cl^1- - 1e^- Cl | Cl + Cl Cl₂ [product Cl₂ gas] Electrometallurgy of aluminium | 22\. Dissociation of pure alumina| Al₂O₃ 2Al³⁺ + 3O^2- 23\. Reaction at cathode [inert - electrode] | 2Al³⁺ + 6e^- 2Al [product AL metal] 24\. Reaction at anode [inert - electrode] | 3O^2- - 6e^- 3[O] 3O₂ [product O₂ gas]

2. B Electrorefining of copper	Complete and balance the electrode reactions
16. Dissociation of aq. copper sulphate	CuSO₄ ⇌ …………… + ……………
	H₂O ⇌ …………… + ……………
17. Reaction at cathode [pure thin sheet of Cu]	Cu²⁺ + …………… ⟶ …………… [Cu deposited on thin sheet]
18. Reaction at anode [impure block of active Cu]	Cu - …………… ⟶ …………… [product nil - Cu²⁺ ions]
Electrometallurgy of sodium
19. Dissociation of sodium chloride fused	NaCl ⇌ …………… + ……………
20. Reaction at cathode [inert - electrode]	Na¹⁺ + …………… ⟶ …………… [product Na metal]
21. Reaction at anode [inert - electrode]	Cl^1- - …………… ⟶ ……………
	Cl + Cl ⟶ …………… [product Cl₂ gas]
Electrometallurgy of aluminium
22. Dissociation of pure alumina	Al₂O₃ ⇌ …………… + ……………
23. Reaction at cathode [inert - electrode]	Al³⁺ + …………… ⟶ …………… [product Al metal]
24. Reaction at anode [inert - electrode]	O^2- - …………… ⟶ …………… ⟶ 3O₂ [product O₂ gas]

2. B Electrorefining of copper	Complete and balance the electrode reactions
16. Dissociation of aq. copper sulphate	CuSO₄ ⇌ *Cu²⁺* + *SO₄^2-*
	H₂O ⇌ *H¹⁺* + *OH^1-*
17. Reaction at cathode [pure thin sheet of Cu]	Cu²⁺ + *2e^-* ⟶ Cu [Cu deposited on thin sheet]
18. Reaction at anode [impure block of active Cu]	Cu - *2e^-* ⟶ *Cu²⁺* [product nil - Cu²⁺ ions]
Electrometallurgy of sodium
19. Dissociation of sodium chloride fused	NaCl ⇌ *Na¹⁺* + *Cl^1-*
20. Reaction at cathode [inert - electrode]	Na¹⁺ + *1e^-* ⟶ Na [product Na metal]
21. Reaction at anode [inert - electrode]	Cl^1- - *1e^-* ⟶ Cl
	Cl + Cl ⟶ *Cl₂* [product Cl₂ gas]
Electrometallurgy of aluminium
22. Dissociation of pure alumina	Al₂O₃ ⇌ *2Al³⁺* + *3O^2-*
23. Reaction at cathode [inert - electrode]	2Al³⁺ + *6e^-* ⟶ *2Al* [product AL metal]
24. Reaction at anode [inert - electrode]	3O^2- - *6e^-* ⟶ *3[O]* ⟶ 3O₂ [product O₂ gas]

1. Electrolysis	Complete and balance the electrode reactions
a. Electrolysis of fused lead bromide
1. Dissociation of lead bromide	PbBr₂ ⇌ …………… + …………… [ions present Pb²⁺, Br^1-] ]
2. Reaction at cathode [inert-graphite]	Pb²⁺ + …………… ⟶ …………… [product Lead metal]
3. Reaction at anode [inert-graphite]	Br^1- - …………… ⟶ …………… Br + Br ⟶ …………… [product Bromine vapours]
b. Electrolysis of acidified water
4. Dissociation of acidified water	H₂SO₄ ⇌ …………… + ……………
	H₂O ⇌ …………… + …………… [ions H¹⁺, SO₄^2-, OH^1-]
5. Reaction at cathode [inert-platinum]	H¹⁺ + …………… ⟶ ……………
	H + H ⟶ …………… [product Hydrogen gas]
6. Reaction at anode [inert-platinum]	OH^1- - …………… ⟶ ……………
	4OH ⟶ …………… + …………… [product oxygen gas]
c. Electrolysis of aq. copper sulphate [Active-copper electrode]
7. Dissociation of aq. copper sulphate	CuSO₄ ⇌ …………… + …………… [ions present — Cu²⁺, H¹⁺, SO₄^2-, OH^1-] H₂O ⇌ …………… + ……………
8. Reaction at cathode [copper (or Pt. or C)]	Cu²⁺ + …………… ⟶ …………… [product copper metal]
9. Reaction at anode [active copper]	Cu - …………… ⟶ …………… [product nil - Cu²⁺ ions]
[Inert-platinum electrode] Dissociation of aq. copper sulphate	CuSO₄ ⇌ …………… + …………… [ions present — Cu²⁺, H¹⁺, SO₄^2-, OH^1-] H₂O ⇌ …………… + ……………
Reaction at cathode [Pt. or Carbon or Cu]	Cu²⁺ + …………… ⟶ …………… [product copper metal]
Reaction at anode [inert-Pt. or C]	OH^1- - …………… ⟶ …………… 4OH ⟶ …………… + …………… [product oxygen gas]

2. A : Electroplating	Complete and balance the electrode reactions
Electroplating of an article with nickle
10. Dissociation of aq. nickle sulphate	NiSO₄ ⇌ …………… + ……………
	H₂O ⇌ …………… + ……………
11. Reaction at cathode [article to be plated]	Ni²⁺ + …………… ⟶ …………… [Ni deposited on article]
12. Reaction at anode [block of active-nickle]	Ni - …………… ⟶ …………… [product nil - Ni²⁺ ions]
Electroplating of an article with silver
13. Dissociation of sodium silver cyanide	Na[Ag(CN)₂] ⇌ …………… + …………… + ……………
	H₂O ⇌ …………… + ……………
14. Reaction at cathode [article to be plated]	Ag¹⁺ + …………… ⟶ …………… [Ag deposited on article]
15. Reaction at anode [block of active-silver]	Ag - …………… ⟶ …………… [product nil - Ag¹⁺ ions]

Chemistry

Electrolysis

Answer

Related Questions

During the electrolysis of molten lead bromide, which of the following takes place ?
Bromine is released at the cathode
Lead is deposited at the anode
Bromine ions gain electrons
Lead is deposited at the cathode

Here is an electrode reaction:
Cu ⟶ Cu²⁺ + 2e^-. [i.e. Cu – 2e^- ⟶ Cu²⁺]
At which electrode (anode or cathode) would such a reaction take place ? Is this an example of oxidation or reduction ?