化學問題[電解]

你要知道稀碘化鈉溶液裏面有什麼離子
正離子有. 鈉和氫
負離子有 碘和氫氧根離子.

電解時, 正極吸引負離子, 而碘離子就會被選擇性氧化. 變碘, 而氫氧根離子不會被氧化.
負極吸引了的正離子, 氫離子被選擇性地還原為氫氣. 而鈉離子則不變.

當溶液裏的氫離子減少時. 就令到溶液的鹼性增加.

2007-01-03 14:14:42 補充：
要弄清楚, 氫氧根離子都會被吸去正極.我估你掉轉左放電的優先次序. iodide碘離子還是優先的．　要高濃度才可放出的應是Cl- 比較electronegative 的element

Sodinm chloride is the major salt in sea water. In electrolysis of sea water, carbon rods are used as electrodes and they are insert. Sodium chloride in the sea water is the electroyte.
The resulting solution becomes colourless sodium hydroxide, which is an alkali. It can turn red litmus paper or pH paper blue.
Useful website:
hwwp://electrochem.cwru.edu/ed/encycl/art-b01-brine.html