摘要
In order to clarify the equilibrium components in the hydrolysis solution of boron trifluoride(BF_3-H_2O),the BF_3-H_2O was prepared by mixing BF_3-CH_3OH with large amount of water,in which the stoichiometric concentration of BF_3 is less than 0.1 mol/L.Two ionic equilibrium models were proposed to simulate the hydrolysis equilibrium of BF_3 and tested by special acid-base titration technique.The most accurate ion equilibrium constants were determined.The model,which was assumed to have no HF,was proved to be more representative for the real system and used to simulate the hydrolysis equilibrium of BF_3.The simulation suggested that H^+,BF_4^-,BF_3OH^- and H_3BO_3 were the main species in the dilute hydrolysis solution,while BF_2(OH)_2^- and F^- were insignificant species whose concentrations were both in the order of 10^(-4) mol/L magnitude,and BF(OH)_3^- could be omitted because its concentration almost equaled zero.Meanwhile,the equilibrium constant of the overall ionic reaction at 25℃ was obtained as 161.6.
In order to clarify the equilibrium components in the hydrolysis solution of boron trifluoride(BF_3-H_2O),the BF_3-H_2O was prepared by mixing BF_3-CH_3OH with large amount of water,in which the stoichiometric concentration of BF_3 is less than 0.1 mol/L.Two ionic equilibrium models were proposed to simulate the hydrolysis equilibrium of BF_3 and tested by special acid-base titration technique.The most accurate ion equilibrium constants were determined.The model,which was assumed to have no HF,was proved to be more representative for the real system and used to simulate the hydrolysis equilibrium of BF_3.The simulation suggested that H^+,BF_4^-,BF_3OH^- and H_3BO_3 were the main species in the dilute hydrolysis solution,while BF_2(OH)_2^- and F^- were insignificant species whose concentrations were both in the order of 10^(-4) mol/L magnitude,and BF(OH)_3^- could be omitted because its concentration almost equaled zero.Meanwhile,the equilibrium constant of the overall ionic reaction at 25℃ was obtained as 161.6.
基金
Supported by the Independent Innovation Fund of Tianjin University(No.1307)
