![](\"https:\/\/cdn.minichemistry.com\/wp-content\/uploads\/2015\/05\/electrolyic-cell.gif\")
<\/p>\n\u2022 Electrolysis is the passage of a direct current through a substance that is either molten or dissolved in a suitable solvent, resulting in chemical reactions at the electrodes and separation of mixtures.<\/p>\n
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\u2022 An ion-electron half reaction occurs at each electrode.<\/p>\n
\u2022 The overall reaction is a redox reaction.<\/p>\n
\u2022 The terminal at which oxidation occurs is the anode whereas the terminal at which reduction occurs is the cathode .<\/p>\n
\u2022 The electrode connected to the positive terminal of the external source of electricity is the positive electrode. The electrode connected to the negative terminal is the negative electrode.<\/p>\n
\u2022 The positive ions in the solution are attracted by the negative electrode. The negative ions are attracted by the positive electrode.<\/p>\n
\u2022 Under certain conditions, a different species in the medium\/set up may be oxidized or reduced in preference to the relevant ions.<\/p>\n
Electrolysis of water (acidic or basic) using inert (carbon or platinum) electrodes<\/strong><\/p>\n At anode; 2H2<\/sub>O(l) \u2192\u00a0O2<\/sub>(g) + 4H+<\/sup>(aq) + 4e Electrolysis of aqueous CuSO4 solution using copper electrodes<\/strong><\/p>\n At anode; Cu(s) \u2192 Cu2+<\/sup>(aq) + 2e Electrolysis of aqueous CuSO4<\/sub> solution using inert electrodes<\/strong><\/p>\n At anode; 2H2<\/sub>O(l) \u2192 O2<\/sub>(g) + 4H+<\/sup>(aq) + 4e Electrolysis of aqueous NaCl solution using inert electrodes<\/strong><\/p>\n At anode; 2Cl–<\/sup>(aq) \u2192\u00a0Cl2<\/sub>(g) + 2e Electrolysis of molten NaCl using inert electrodes<\/strong> <\/p>\n (1) The quantity of a substance liberated at an electrode is directly proportional to the quantity of electric charge that has flowed in the circuit.<\/p>\n (2) For a given quantity of electric charge, the amount of any metal deposited is proportional to its equivalent weight (atomic weight devided by the charge on the metal ion) \u2022 Electroplating means coating a metal with another metal using electricity. This is different from the deposition of a less reactive metal on a more reactive metal.<\/p>\n In order to have a quality coating during electrolysis, the coating should strongly bind with the metal. In addition, it should have the following qualities.<\/strong> \u2022 Lustre<\/p>\n \u2022 Chemical inertness<\/p>\n \u2022 Good mechanical properties<\/p>\n \u2022 Absence of cracks and holes<\/p>\n \u2022 Uniformity in thickness and appearance<\/p>\n <\/p>\n To get a quality metal coating the following factors should be appropriately controlled.<\/strong> \u2022 Concentration of ions<\/p>\n \u2022 Temperature<\/p>\n \u2022 Current density<\/p>\n \u2022 pH value<\/p>\n \u2022 Nature of the other ions presents<\/p>\n \u2022 Potential difference<\/p>\n \u2022 Purity of the anode<\/p>\n \u2022 Relative positioning of the anode and the cathode<\/p>\n \u2022 Cleanliness of the object and the nature of its surface<\/p>\n <\/p>\n Two or more reactions may also occur simultaneously on the electrodes. They can be controlled by changing the temperature, concentration, voltage and the nature of electrodes.<\/p>\n","protected":false},"excerpt":{"rendered":" \u2022 Electrolysis is the passage of a direct current through a substance that is either molten or dissolved in a suitable solvent, resulting in chemical reactions at the electrodes and separation of mixtures. Principles of electrolysis \u2022 An ion-electron half reaction occurs at each electrode. \u2022 The overall reaction is a redox reaction. \u2022 […]<\/p>\n","protected":false},"author":842,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[14,1678],"tags":[],"class_list":["post-6050","post","type-post","status-publish","format-standard","hentry","category-chemistry","category-unit-14"],"acf":[],"yoast_head":"\n
\nAt cathode; 2H2<\/sub>O(l) + 2e \u2192 H2<\/sub>(g) + 2OH–<\/sup>(aq)<\/p>\n
\nAt cathode; Cu2+<\/sup>(aq) + 2e \u2192\u00a0Cu(s)<\/p>\n
\nAt cathode; Cu2+<\/sup>(aq) + 2e \u2192\u00a0Cu(s)<\/p>\n
\nAt cathode; 2H2<\/sub>O(l) + 2e \u2192 H2<\/sub>(g) + 2OH–<\/sup>(aq)<\/p>\n
\nAt anode; 2Cl–<\/sup>(l) \u2192 Cl2<\/sub>(g) + 2e
\nAt cathode; Na+<\/sup>(l) + e \u2192 Na(l)<\/p>\nFaraday’s Laws<\/h4>\n
\nFaraday’s constant (F) = Molar charge of a proton \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 = \u00a01.602 x 10-19 C x 6.022 x 1023 mol-1= 96 484 C mol-1<\/sup>\u224596 500 C mol-1<\/sup><\/p>\nElectroplating<\/h4>\n
\n\u2022 Strength<\/p>\n
\n\u2022 The nature and purity of the electrolyte<\/p>\n