Finding the pKa Values of a Double-Range Indicator Thymol Blue in a Remote Learning Activity
Finding the pKa Values of a Double-Range Indicator Thymol Blue in a Remote Learning Activity
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在远程学习活动中查找双量程指示剂百里酚蓝的 pKa 值
DOI：
10.1021/acs.jchemed.1c00122
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发表时间：
2021
影响因子：
3
通讯作者：
Manchuta Dangkulwanich
中科院分区：
文献类型：
--
作者：
Warangkana Yimkosol;Manchuta Dangkulwanich
各种酸碱指示剂的彩色跃迁已被用来说明化学平衡的概念，特别是在分光光度法测定平衡常数或pak值时。为了适应COVID-19大流行所需的在线实验室环境，本工作采用数字图像的颜色分析来确定双范围指示剂百里香酚蓝的pkk值。该实验已发展成为一个在线活动，教化学平衡和解离的二质子酸。学生测得的pka1和pka2值分别为1.60±0.05和8.70±0.06，与文献值吻合较好。结果表明，在不使用分光光度计的情况下，RGB颜色分析在测定百里香酚蓝的pkk值方面具有强大的应用价值。
Colorful transitions of various acid–base indicators have been used to illustrate the concept of chemical equilibria, especially in spectrophotometric determination of the equilibrium constants or pKavalues. To accommodate an online laboratory environment necessitated by the COVID-19 pandemic, this work employs color analyses from digital images to determine the pKavalues of a double-range indicator thymol blue. The experiment has been developed into an online activity to teach chemical equilibria and dissociation of a diprotic acid. The pKa1and pKa2values determined by students are in good agreement with the literature values at 1.60 ± 0.05 and 8.70 ± 0.06, respectively. The results demonstrate a powerful application of RGB color analyses in determination of the pKavalues of thymol blue without access to spectrophotometers.