點先可以將sodium chloride分解?

If u want to electrolyse sodium chloride, u have to dissolve sodium chloride into water first to make a highly concentrated aqueous sodium chloride solution. Use carbon and mercury as electrodes. During electrolysis, sodium ion will gain a electron and combine with mercury to form sodium-mercury alloy and chloride will lose a electron to form chlorine gas from carbon electrode. Heating up of sodium-mercury alloy will vapourize the mercury to leave pure sodium becuase of diifferent boiling point.

電解極稀氯化鈉溶液：

稀的定義是2M或以下, 題目時稀溶液就是2M
當NaCl的濃度為2M或以上, 電解時Cl-優先放電
當NaCl的濃度為0.5M或以下, OH-優先放電

1. Solubility of water [在水的溶解度]
Sodium chloride dissolves in water
[Sodium chloride 係 ionic compound {polar}，而水係polar，所以like dissolves like]
But quartz does not
2. Electrical conductivity [導電性]
Sodium chloride – electrolyte
[Electrolyte – can conduct electricity in molten (i.e. liquid) and aqueous state]
In liquid state -> NaCl (l) -> Na+ (l) + Cl- (l)
In aqueous state -> NaCl (aq) -> Na+ (aq) + Cl- (aq)
-> as mobile ions [i.e. Na+, Cl-] exists
Quartz – cannot conduct electricity
-> no charge carrier [i.e. no mobile ions/ electrons]