Hydrolytic equilibria of metallic ions : II. The hydrolysis of Fe(II) ion in NaClO<sub>4</sub> solutions
The acidic ionization (hydrolysis) constant of ferrous ion has been measured in the range of temperature between 20 and 40°C and of ferrous ion concentration between 0·0016 and 0·062 M, in 0·5 to 2 M sodium perchlorate solution, according to the theory of the constant ionic medium. The value of pKa′...
Guardado en:
| Autores principales: | , |
|---|---|
| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
1963
|
| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/121247 |
| Aporte de: |
| Sumario: | The acidic ionization (hydrolysis) constant of ferrous ion has been measured in the range of temperature between 20 and 40°C and of ferrous ion concentration between 0·0016 and 0·062 M, in 0·5 to 2 M sodium perchlorate solution, according to the theory of the constant ionic medium. The value of pKa′ obtained at 25°C is 6·74 ± 0·06. Within experimental error Ka′ is independent of the ferrous ion and sodium perchlorate concentrations. The temperature dependence of Ka′ is expressed by pKa′=2625T-2-037. The increase of enthalpy and free energy of the hydrolysis reaction are: ΔH<sub>298°</sub> = 12,000 ± 1,000 cal/mol; ΔG<sub>298°</sub> = 9,165 ± 100 cal/mol. The information has been used to draw conclusions on the character of the ferrous ion in aqueous solution; on its amphoteric nature; and for checking the solubility data of ferrous hydroxide. |
|---|