物理化学学报 >> 2016, Vol. 32 >> Issue (5): 1134-1142.doi: 10.3866/PKU.WHXB201602194

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NH4VO3在NH4H2PO4-H2O和(NH4)3PO4-H2O体系中的溶解度

公绪莉1,2,张长桥1,*(),宁朋歌2,*(),曹宏斌2,张懿2   

  1. 1 山东大学化学与化工学院,济南250100
    2 中国科学院过程工程研究所绿色过程工程重点实验室,北京100190
  • 收稿日期:2015-11-26 发布日期:2016-05-07
  • 通讯作者: 张长桥,宁朋歌 E-mail:zhangchqiao@sdu.edu.cn;pgning@ipe.ac.cn
  • 基金资助:
    国家科技支撑计划(2015BAB02B05);国家重点基础研究发展规划项目(973)(2013CB632605);和国家自然科学基金项目(51425405)

Solubility of NH4VO3 in NH4H2PO4-H2O and (NH4)3PO4-H2O Systems

Xu-Li GONG1,2,Chang-Qiao ZHANG1,*(),Peng-Ge NING2,*(),Hong-Bin CAO2,Yi ZHANG2   

  1. 1 School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
    2 Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China
  • Received:2015-11-26 Published:2016-05-07
  • Contact: Chang-Qiao ZHANG,Peng-Ge NING E-mail:zhangchqiao@sdu.edu.cn;pgning@ipe.ac.cn
  • Supported by:
    the Technology Support Program of China(2015BAB02B05);National Basic Research Program of China (973)(2013CB632605);National Natural Science Foundation of China(51425405)

摘要:

采用等温溶解法测定了偏钒酸铵(NH4VO3)在NH4H2PO4-H2O和(NH4)3PO4-H2O体系中T = 298.15-328.15 K时的溶解度以及溶液的密度和pH值。结果表明, NH4VO3的溶解度随着(NH4)3PO4或NH4H2PO4溶液浓度的增大,先降低后升高,这是由于同离子效应、化学反应平衡及离子活度的共同作用。比较T = 298.15K时, NH4VO3分别在NH4H2PO4-H2O、(NH4)2HPO4-H2O和(NH4)3PO4-H2O体系中溶解度,发现在相同的磷酸盐浓度下, NH4VO3的溶解度在NH4H2PO4-H2O体系中最大,在(NH4)3PO4-H2O体系中居中,在(NH4)2HPO4-H2O体系中最小。进一步地,在T = 298.15 K和磷酸盐浓度C = 0.5 mol·kg-1时,结合pH值和反应溶度积常数KSP等计算三个体系中的平均离子活度系数(γ±),发现γ±值在(NH4)2HPO4-H2O体系中最大,在(NH4)3PO4-H2O体系中居中,在NH4H2PO4-H2O体系中最小,与溶解度规律一致。

关键词: 偏钒酸铵, 溶解度, NH4H2PO4溶液, (NH4)3PO4溶液

Abstract:

The solubility of ammonium metavanadate (NH4VO3) in NH4H2PO4-H2O and (NH4)3PO4-H2O systems at T = 298.15-328.15 K was measured using the classic isothermal dissolution method. The densities and pH values of the solutions were also determined. The solubility of NH4VO3 decreased at first and then increased with increasing NH4H2PO4 or (NH4)3PO4 concentrations. This was considered to be caused by the common ionic effect, chemical reaction equilibrium and ionic activity. At T = 298.15 K, the solubility of NH4VO3 in the NH4H2PO4-H2O system was the highest, and was lower in the (NH4)3PO4-H2O system. The solubility in the (NH4)2HPO4-H2O system was the lowest. The mean ionic activity coefficients were calculated for the three phosphate solutions at C = 0.5 mol·kg-1 using the pH values and dissolution reaction constant. The mean ionic activity coefficients were the largest for the (NH4)2HPO4-H2O system, and were smaller for the (NH4)3PO4-H2O system. The mean ionic activity coefficients were the smallest for the NH4H2PO4-H2O system, which agrees with the solubility variations of NH4VO3 in the three phosphate systems.

Key words: NH4VO3, Solubility, NH4H2PO4 solution, (NH4)3PO4 solution

MSC2000: 

  • O642