From a pastpaper question:
When water is added to CuCl2, it dissolves.
So it won't form complex [Cu(H2O)4)^2+?
Because AlCl3 will from complex in water and gives acidic property by:
AlCl3 + 6H2O -> [Al(H2O)6]3+(aq) + 3Cl-(aq)
[Al(H2O)6]3+(aq) -> [Al(H2O)5(OH)]2+(aq) + H+(aq)
So why CuCl2 does not react in the same way?
Thanks!
Will CuCl2 form complex in H2O
2010-03-24 6:37 am
回答 (2)
2010-03-25 4:34 am
✔ 最佳答案
Cu2+個charge唔夠Al3+咁高又唔夠Al3+咁細
所以Cu2+既charge density同polarizing power唔夠Al3+咁高
亦因此令到Cu2+唔足以令水分子既O─H bond更加polar而令個H甩出黎
所以[Cu(H2O)4]2+好難出一個咁樣既complex：[Cu(H2O)3(OH)]+
喺度講多少少
我地可以睇睇下面條equation
[Cu(H2O)4]2+ + H2O → [Cu(H2O)3(OH)]+ + [H3O]+
上面果個ionization既pKa就會比[Al(H2O)6]3+細得多 (基於上述原因)
但喺alkaline condition，因為H+既濃度細好多，個equilibrium就會shift去右手邊，咁先會出[Cu(H2O)3(OH)]+
所以一般黎講CuCl2溶落水唔會學Al3+咁放H+
2010-03-24 7:00 am
i think it is because cu is not as reactive as al
just like reaction with H2O
cu won't react with water while al would.=]]
just like reaction with H2O
cu won't react with water while al would.=]]
收錄日期: 2021-04-13 17:09:59
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100323000051KK01795