양쪽성 [Al(H2O)3(OH)3] 양쪽성

양쪽성 [Al(H2O)3(OH)3] 양쪽성

amphoteric [Al(H2O)3(OH)3] amphoteric

 

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▶ 참고: 양쪽성양성자성(amphiprotic) 물질

[ https://ywpop.tistory.com/2703 ]

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AlCl3(s) + H2O(l) → [Al(H2O)6]^3+(aq) + 3Cl^-(aq)

( 참고 https://ywpop.tistory.com/3043 )

 

 

 

 

According to Pearson,

the aluminium ion is a hard acid

and therefor has a tendency to react with

hydroxide ions as a hard base.

( 참고 https://ywpop.tistory.com/12212 )

 

 

The hydrolysis of the aluminium ion

depends on pH of the aqueous environment.

 

 

Aluminium complexes are octahedral

and hence have six ligands.

 

 

At pH < 4 the dominant species is [Al(H2O)6]^3+

while at pH > 3 hydroxide ions begin to join the complex.

 

 

The pH-dependent reactions

whose describe the amphoteric character of aluminium hydroxide

are listed below.

 

 

 

▶ pH 3 ~ 7

[Al(H2O)6]^3+(aq) + H2O(l) ⇌ [Al(H2O)5OH]^2+(aq) + H3O^+(aq)

 

 

▶ pH 4 ~ 8

[Al(H2O)5OH]^2+(aq) + H2O(l) ⇌ [Al(H2O)4(OH)2]^+(aq) + H3O^+(aq)

 

 

▶ pH 4 ~ 9

[Al(H2O)4(OH)2]^+(aq) + H2O(l) ⇌ [Al(H2O)3(OH)3](s) + H3O^+(aq)

 

 

▶ pH > 6

[Al(H2O)3(OH)3](s) + H2O(l) ⇌ [Al(H2O)2(OH)4]^-(aq) + H3O^+(aq)

 

 

 

[출처] Electrochemical Removal and Kinetics in the Removal of Fluoride from Underground Water in Kenya

> 저자: Stuede Grit, Maghanga Justin, Ulrike Feistel, Matata Koti, Segor Fred

 

 

 

 

▶ NaOH solution

[Al(H2O)6]^3+ → [Al(H2O)3(OH)3]

 

 

▶ excess NaOH solution

[Al(H2O)3(OH)3] → [Al(H2O)3(OH)4]^-

 

 

 

 

[키워드] amphoteric 기준문서, 양쪽성 기준문서, [Al(H2O)6]^3+ 기준문서 [Al(H2O)6]^3+ dic