72, Hafnium (Hf)
lat. hafnia = Kopenhagen |
Säure-Base-Verhalten:
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Säure/Base-Verhalten der Hafnium-Oxide: |
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Reaktionen mit: |
HF 100% |
H2SO4 conc. |
HCl 20% |
CH3COOH 25% |
H2O |
NH3 25% |
NaOH 10% kalt |
NaOH 50% heiß |
NaOH liq. 400°C |
[1]HfO2 |
HfF4 |
Hf(SO4)2 |
HfOCl2 |
(CH3COO)2HfO |
Hf(OH)4↓ |
Hf(OH)4↓ |
Na2Hf(OH)6 |
Na2Hf(OH)6 |
Na2HfO3 |
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Legende: |
Lösung |
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Unlöslich |
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sauer → neutral → alkalisch |
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pKS-Werte von Säure-Base-Paaren (HA + H2O ↔ H3O+ + A-) : |
Säurename |
Formel |
pKS-Wert |
Basenname |
Formel |
pKB-Wert |
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Hafnium(IV)-Ion |
Hf4+ |
-0.12 |
Hydroxo-Hafnium(IV)-Ion |
Hf(OH)3+ |
14.12 |
Hydroxo-Hafnium(IV)-Ion |
Hf(OH)3+ |
0.23 |
Dihydroxo-Hafnium(IV)-Ion |
Hf(OH)22+ |
13.77 |
Dihydroxo-Hafnium(IV)-Ion |
Hf(OH)22+ |
0.42 |
Trihydroxo-Hafnium(IV)-Ion |
Hf(OH)3+ |
13.58 |
Trihydroxo-Hafnium(IV)-Ion |
Hf(OH)3+ |
0.52 |
Hafnium(IV)hydroxid |
Hf(OH)4 |
13.48 |
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