Dissociation pressure of lanthanum dioxide carbonate

Heat capacities and entropies of La2O2CO3fromT= (12 to 300) K and of Nd2O2CO3fromT= (12 to 930) K, and their interpretation

“…The electronic heat capacity coefficient γ = 0 within experimental uncertainty. In (11) Based on our data, the entropy of formation of La 2 O 2 CO 3 from La 2 O 3 (17) and CO 2 (18) at T = 300 K is −170.2 J·K −1 ·mol −1 . Watanabe et al (11) report the value to be −126 J·K −1 ·mol −1 .…”

“…In (11) Based on our data, the entropy of formation of La 2 O 2 CO 3 from La 2 O 3 (17) and CO 2 (18) at T = 300 K is −170.2 J·K −1 ·mol −1 . Watanabe et al (11) report the value to be −126 J·K −1 ·mol −1 . The latter is a median value for T = (1000 to 1300) K, and the discrepancy may, in part, result from the temperature dependence of the formation entropy.…”

“…The adopted thermodynamic data for Nd 2 O 3 were taken from references 17 and 19. Due to the limited temperature range of the decomposition study, (11) the uncertainty associated with the enthalpy and entropy of decomposition values should be expected to be substantial.…”

“…The dilanthanum dioxide carbonate is more stable than the dineodymium dioxide carbonate. Whereas La 2 O 2 CO 3 decomposes at T = 1180 K (11) at p(CO 2 ) ≈ 1.013·10 5 Pa, Nd 2 O 2 CO 3 is stable up to T = (1088 ± 10) K only. (9) Watanabe et al (11) have determined the standard molar Gibbs free energy of decomposition of La 2 O 2 CO 3 .…”

“…Whereas La 2 O 2 CO 3 decomposes at T = 1180 K (11) at p(CO 2 ) ≈ 1.013·10 5 Pa, Nd 2 O 2 CO 3 is stable up to T = (1088 ± 10) K only. (9) Watanabe et al (11) have determined the standard molar Gibbs free energy of decomposition of La 2 O 2 CO 3 . From experimental decomposition pressures in the temperature region from T = (1000 to 1300) K, the median standard molar enthalpy and entropy of decomposition are reported to be 149 kJ·mol −1 and 126 J·K −1 ·mol −1 .…”