摘要
溴化稀土在948K以下时蒸气压极小,以至于无法测出。研究显示,可能是由于生成气态配合物NdyAlxBr3(x+y),溴化钕与溴化铝在600K以上共热时,溴化钕的表观蒸气压大幅度提高。平衡实验结果表明,在温度为629～805K和压力为0.015～0.19MPa时,NdAl3Br12是惟一的稳定气态配合物。反应式NdBr3(s)+(3/2)Al2Br6(g)=NdAl3Br12(g)的平衡常数由骤冷实验结果计算。假设ΔC p=0J·mol-1·K-1,该反应的焓变和熵变分别为ΔH 298=-2.6±3.0J·mol-1·K-1。298=25.5±2.
When temperature is below 948 K, the vapour pressure of rare earth bromides is immeasurably small. But experiments show that, when it heat together with aluminum bromide at above 600 K, the apparent vapour pressure of neodymium bromide may obviously increase. That may be caused by the formation of vapour complexes Nd_yAl_xBr_(3(x+y). Equilibrated quenching experimental results for the (NdBr_3+AlBr_3 system show that the NdAl_3Br_(12) complex is the sole predominant vapour complex roughly at the temperature of 629～805 K and under pressure of (0.015)～0.19 MPa. Changes in thermodynamic properties of the reaction were calculated from the reaction equilibrium constants. The results show that ΔH~_(298) is 25.5±2.0 kJ·mol^(-1) and ΔS~_(298) is -2.6±3.0 J·mol^(-1)·K^(-1) with the assumption of ΔC~_p is 0 J·mol^(-1)·K^(-1).
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2004年第4期702-705,共4页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(50274027)
