摘要
酚酞是最常见的酸碱指示剂之一,在pH〈8.2时,酚酞溶液不显色,当8.212.0时,酚酞会慢慢褪色,直至呈无色。利用酚酞在碱性溶液中慢慢褪色的过程,通过测定溶液吸光度的变化,测定酚酞在碱性溶液中反应的速率常数和反应级数,使学生进一步理解化学反应动力学的基本概念。
Phenolphthalein is one of the most common acid-base indicators. It is colorless when pH is below 8.2 and red when pH is between 8.2 and 10.0. But little attention was paid to the phenomenon of phenolphthalein fading slowly and colorless eventually in strong alkaline solution. By measuring absorbance change of solution of phenophthalein while it fades slowly in strong alkaline solution, rate constant and reaction order of phenolphthalein are determined. This experiment can help students understand basic concepts of chemical kinetics better.
出处
《化学教育》
CAS
北大核心
2014年第24期26-28,共3页
Chinese Journal of Chemical Education
关键词
酚酞指示剂
吸光度
速率常数
反应级数
phenolphthalein indicator
absorbance
rate constant
reaction order
