電解海水一問 幫幫忙 15點!!!

在課本上也是很長的一段，很難簡述，不如你睇完書之後有什麼看不明白的地方再提出來發問啦！

最簡單是陽極吸引陰離子，在濃溶液的情況是放 Cl₂ 而不是 O₂。

在陰極會吸引陽離子，放出 H₂。

剩下來的水溶液最後成為 NaOH。

With the reference to the electrochemical series:
(1)H+ has a lower position than Na+
H+ receives electrons more readily
(2)OH- has a higher position than Cl- compared at 1M concentration
OH- losses electrons more readily

However, due to the concentration effect, if the concentration of Cl- increases, Cl- will has a higher tendencies to lose electrons than OH-. In this case, Cl- will be oxidized to Cl2 and Cl- is said to be discharged preferentially than OH-.

2Na+ + H2O --> 2NaOH + H2

cathode: 2H+ +2e- --> H2

anode: 2Cl- -->Cl2 + 2e-