摘要
Hydrated potassium monoborate(KBO 2 ·4/3H 2 O)was obtained from an aqueous solutio n in a mole ratio of K 2 O∶B 2 O 3 =2∶1and characterized by powder X-ray diffraction(XRD),infrared spectroscopy(FT-IR)and Raman spectroscopy.The enthalpy of solut ion of hydrated potassium monoborate,KBO 2 ·4/3H 2 O,in approximately1mol·dm -3 aqueous hydrochloric acid was determined.Together with the previously determined enthalpies of so-lution of H 3 BO 3 in approximately 1mol·dm -3 HCl (aq),and of KCl in aqueous(hydrochloric acid +boric acid),the standard molar enthalpy of forma tion of -(1411.11±0.84)kJ·mol -1 for KBO 2 ·4/3H 2 O was obtained from the standard molar enthalpies of formation of KCl (s),H 3 BO 3 (s),and H 2 O(l).The standard molar entropy of formation of -422.94J ·K -1 ·mol -1 and standard molar entropy of 163.47J·K -1 ·mol -1 for KBO 2 ·4/3H 2 O were calculated from the thermodynamic relations.A group contribution method is applicable to KBO 2 ·4/3H 2 O.
Hydrated potassium monoborate (KBO2 . 4/3H(2)O) was obtained from an aqueous solution in a mole ratio of K2O: B2O3 = 2: 1 and characterized by powder X-ray diffraction (XRD), infrared spectroscopy (FT-IR) and Raman spectroscopy. The enthalpy of solution of hydrated potassium monoborate, KBO2 . 4/3H(2)O, in approximately 1mol . dm(-3) aqueous hydrochloric acid was determined. Together with the previously determined enthalpies of solution of H3BO3 in approximately 1mol . dm(-3) HCl (aq) and of KCl in aqueous (hydrochloric acid + boric acid), the standard molar enthalpy of formation of - ( 1411.11 +/- 0. 84) kJ . mol(-1) for KBO2 . 4/3H(2)O was obtained from the standard molar enthalpies of formation of KCl(s), H3BO3(S), and H2O(l). The standard molar entropy of formation of - 422. 94J . K-1 . mol(-1) and standard molar entropy of 163. 47J . K-1 mol (-1) for KBO2 . 4/3H(2)O were calculated from the thermodynamic relations. A group contribution method is applicable to KBO2 . 4/3H(2)O.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2003年第3期333-336,共4页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金资助课题(No.20271051)。
关键词
水合偏硼酸钾
标准摩尔生成焓
溶解量热法
溶解焓
KBO2
4/3H(2)O
standard molar enthalpy of formation
solution calorimetry
molar enthalpy of solution
