ELECTROLYSIS OF BRINE
細佬今年F4 E家D阿SIR係咁教D勁難既野又唔解釋 佢話遲D上到高FROM 你就識 搞到我乜都唔識-.-所以問下咁多位讀CHEM 既
我明水電解既概念
電將H2O 變成 H+ 同 (O)2-
之後就分別被負同正極吸引
之後就變H2 同O2 升左上去
但係電解鹽水 就唔明
照番上面個概念
就變成 NA+ CL- H+ 同(O)2-
之後因為NA+ 好難變番NA 所以唔理佢 留番係SOLUTION 到
之後H+就去負極啦 之後變H2 升上去
CL-同(O)2- 就去正極 之後變 CL2 同O2 升上去
問題黎啦 正確答案係 負極係H2 但係正極 得CL2
O係同H變左HYDROXIDE 同NA REACT 變左 NAOH 留左係SOLUTION
之後我上網查
查到DISSOCIATION E樣野
但係我唔明點解水唔會好似水解咁變成H+同(O)2-
反而變成H+ 同OH-
都係搵電電水姐-.- 見到個標題以為有人呃POST 話說我讀左3年...
e+中6喇
我修英文phy+chem
都唔係好明....
加油啦 high concentration of cl ions 搵我嗎??
補習啦,學校D老師9成9都係垃圾 本帖最後由 adason20 於 24-9-2012 18:07 編輯
因為brine 係 concentrated sodium chloride solution, cl- 之所以會discharged 成cl2 係due to concentration effect ( for anions only; 與anions 既reducing power 排名無關) AND 你唔明 水會ionize 成H+ AND OH- 而唔係 O2-
你可以咁既理解:
Distilled water 係 neutral (pH exactly= 7)
--> imply 左 酸度 同 鹼度 equal
--> acidic property 係due to H+ : alkaline property 係 due to OH-
所以如果要neutral, 水係要h+ and oh- balance
希望你明 本帖最後由 櫻之道 於 26-9-2012 14:24 編輯
電將H2O 變成 H+ 同 (O)2-之後就分別被負同正極吸引 之後就變H2 同O2 升左上去
(Wrong concept. Should be OH- attracted by positive to become O2 and then evolved. Not O2-)
但係電解鹽水 就唔明 照番上面個概念 就變成 NA+ CL- H+ 同(O)2-之後因為NA+ 好難變番NA 所以唔理佢 留番係SOLUTION 到 之後H+就去負極啦 之後變H2 升上去
(Up to here is correct)
CL-同(O)2- 就去正極 之後變 CL2 同O2 升上去
(Again, should be OH-)
問題黎啦 正確答案係 負極係H2 但係正極 得CL2 O係同H變左HYDROXIDE
(O 自己無啦啦唔會同H走埋一齊變OH-. Concept錯。atom5會自己react Actually Cl- is attracted to the positive pole and become chlorine gas due to its higher priority to be oxidized, so the remaining OH- is not oxidized to O2, thus accommodate in the solution and combine with the remaining Na+ (which is not reduced due to similar reason) to become NaOH.)
同NA REACT 變左 NAOH 留左係SOLUTION 之後我上網查 查到DISSOCIATION E樣野 但係我唔明點解水唔會好似水解咁變成H+同(O)2-反而變成H+ 同OH-都係搵電電水姐-.- 我地教緊BK 1B
你地BK1? (Wrong concept. Should be OH- attracted by positive to become O2 and then evolved. Not O2-)
唔明
照E家我所學 電應該將所有BOND BREAK DOWN 變番最原始既ELEMENT 點解OH- 唔會變左O同H?
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