摘要
运用化学反应的焓变与熵变，从化学热力学的角度，计算说明了如果空气中二氧化碳的含量按文献值即体积浓度为0．03％上下各浮动20％，求得碳酸钠分解温度为1227．69℃和1203．74℃，用酒精灯加热不能达到；碳酸氢钠分解温度为54．56℃和50．9℃，用酒精灯加热很容易达到；故用酒精灯加热只能使碳酸氢钠分解产生二氧化碳，而碳酸钠则不能。
From the perspective of chemical thermodynamics, through calculation using en- thalpy and entropy change of chemical reaction, this paper showed that if the volume concentra- tion of carbon dioxide in the air was floated up and down 20% from the literature value 0. 03%, the decomposition temperatures of sodium carbonate were 1 227. 69℃ and 1 203.74℃ respectively, which alcohol burner could not achieve, and the decomposition temperatures of sodium bi- carbonate were 54. 56℃ and 50. 9℃ respectively, which alcohol burner was easy to achieve, so alcohol burner could only made sodium bicarbonate decompose to produce carbon dioxide, but not sodium carbonate.
出处
《化学教育》
CAS
北大核心
2016年第15期71-72,共2页
Chinese Journal of Chemical Education
基金
衡水学院2014年度教改资金资助课题(jg2014073)
关键词
焓变
熵变
化学热力学
碳酸钠
碳酸氢钠
分解温度
enthalpy change
entropy change
chemical thermodynamics
sodium carbonate
sodium bicarbonate
decomposition temperature
