Calculation of thermodynamic properties of hydrated borates by group contribution method

Minimizing water utilization in hydrolysis of sodium borohydride: The role of sodium metaborate hydrates

“…Li et al [15] developed general (Eqs. (2) and (3)), based on the group contribution method, to correlate and predict the thermodynamic properties of hydrated borates based on structure.…”

“…(2) and (3) and the properties obtained from literature (Table 2), the heat of formation and Gibbs free energy were calculated for borates at different degrees of hydration [15]. Results are given in Table 3.…”

“…The literature has insufficient thermochemical information on hydrated borates and how thermodynamic properties of the hydrated borates change as a function of degree of hydration. A group contribution method [15] will be used to estimate the Gibbs free energy ( G 0 f ) and the heat of formation ( H 0 f ) of the sodium borates.…”

Thermodynamic properties of Cs2[B4O5(OH)4]·3H2O

“…From these data, the standard molar enthalpy of formation of Cs 2 [B 4 O 5 (OH) 4 ] AE 3H 2 O was calculated to be À(4859.23 ± 0.64) kJ AE mol À1 . The enthalpy of formation of Cs 2 [B 4 O 5 (OH) 4 ] AE 3H 2 O can also be estimated by a group contribution method [10], which can be expressed in the following equation: [10], the D f H m of À258.28 kJ AE mol À1 of Cs + was taken from the NBS tables [3].The standard molar enthalpy of formation is, using this scheme, À4852.28 kJ AE mol À1 . The relative error is 0.14%.…”

“…We also used a group contribution method to calcu- 4 ] 2À and À237.28 kJ AE mol À1 of structural H 2 O were taken from the literature [10], and the D f G m of À292.02 kJ AE mol À1 of Cs + was taken from the NBS tables [3]. Combining …”