[AL CHEM] 用咩方法分辮 Na2CO3 & NaHCO3?

2007-03-13 3:22 am
可以用咩化學方法來分辮 Na2CO3 & NaHCO3?
更新1:

點解Na2CO3受熱不分解,而NaHCO3受熱會分解?

回答 (3)

2007-03-13 3:48 am
✔ 最佳答案
由於Na2CO3受熱不分解,而NaHCO3受熱會分解

反應方程如下:
2NaHCO3(aq) -- > (加熱)H2O(l)+CO2(g)+Na2CO3(aq)

因此只要將Na2CO3和NaHCO3分別加熱,

再將生成氣體通入石灰水< Ca(OH)2 >中,

由於NaHCO3加熱生成了CO2的關係,

所以能令石灰水變渾濁的,就是NaHCO3,

反之就是Na2CO3

2007-03-15 19:57:17 補充:
**因為NaHCO3的熱穩定性較Na2CO3低
2007-03-16 8:33 pm
The other answer is more simple & direct.
2007-03-13 11:00 pm
to be simple,

dissolve both solid into water, and then add ZnCl2 (aq).

The one with ppt is Na2CO3 (since ZnCO3 is insoluble in water)

the one without ppt is NaHCO3 (since Zn(HCO3)2 is soluble in water)


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