10.1021/ie302439u.s001
Hesheng Yu
Hesheng
Yu
Zhongchao Tan
Zhongchao
Tan
Determination
of Equilibrium Constants for Reactions
between Nitric Oxide and Ammoniacal Cobalt(II) Solutions at Temperatures
from 298.15 to 309.15 K and pH Values between 9.06 and 9.37 under
Atmospheric Pressure in a Bubble Column
American Chemical Society
2013
equilibrium constants
9.37
equations ln KNO 5
pH
NH
fraction molar basis
9.06
Co
ln KNO 6
2 H 2O
298.15
rH
kJ
2013-03-13 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Determination_of_Equilibrium_Constants_for_Reactions_between_Nitric_Oxide_and_Ammoniacal_Cobalt_II_Solutions_at_Temperatures_from_298_15_to_309_15_K_and_pH_Values_between_9_06_and_9_37_under_Atmospheric_Pressure_in_a_Bubble_Column/2434819
Experiments were conducted in a bubble
column to determine the
equilibrium constants of reactions between NO and ammoniacal cobalt(II)
solutions at temperatures between 298.15 and 310.15 K and pH values
from 9.06 to 9.37 under atmospheric pressure. The two reactions are
2Co(NH<sub>3</sub>)<sub>5</sub>(H<sub>2</sub>O)<sup>2+</sup> + 2NO
⇌ (NH<sub>3</sub>)<sub>5</sub>Co(N<sub>2</sub>O<sub>2</sub>)Co(NH<sub>3</sub>)<sub>5</sub><sup>4+</sup> + 2H<sub>2</sub>O and
2Co(NH<sub>3</sub>)<sub>6</sub><sup>2+</sup> + 2NO ⇌ (NH<sub>3</sub>)<sub>5</sub>Co(N<sub>2</sub>O<sub>2</sub>)Co(NH<sub>3</sub>)<sub>5</sub><sup>4+</sup> + 2NH<sub>3</sub>, respectively. Their
equilibrium constants are calculated on the fraction molar basis.
All experimental data fit well to the equations ln <i>K</i><sub>NO</sub><sup>5</sup> = 3598.5(1/<i>T</i>) + 16.759 and ln <i>K</i><sub>NO</sub><sup>6</sup> = 1476.4(1/<i>T</i>) + 26.597, which give the enthalpy of reactions between NO and penta-
and hexaamminecobalt(II) nitrates: Δ<sub>r</sub><i>H</i><sub>5</sub>° = −29.92kJ·mol<sup>–1</sup> and Δ<sub>r</sub><i>H</i><sub>6</sub>° = −12.27kJ·mol<sup>–1</sup>.