phenolphthalein

简明释义

英[fəˈnɒlθeɪˌliːn]美[fəˈnɒlθeɪˌliːn]

n. [试剂] 酚酞（一种测试碱性的试剂，可作刺激性泻剂）

英英释义

单词用法

同义词

反义词

例句

1.Acid calibration potassium hydroxide, to phenolphthalein as indicator.

钾标定，以酚酞为指示剂。

2.Soluble in water, its aqueous solution is strongly alkaline, can phenolphthalein red.

易溶于水，其水溶液呈强碱性，能使 酚酞变红。

3.A kinetic method for the direct determination of CO_2 in gaseous phase is proposed, based on fading the phenolphthalein when CO_2 dissolves in dilute aqueous solution of NaOH.

本文基于气相中的二氧化碳在稀氢氧化钠-酚酞溶液中的溶解而使酚酞逐渐褪色的动力学行为提出了一种直接测定气相中微量二氧化碳的动力学分析法。

4.In order to increase reliability using phenolphthalein solution to detect alkaline cell sealing characteristics, the water in the alcohol was decreased, environment humidity were requisite.

为了提高酚酞溶液检测碱性电池密封性能的可靠性，就必须减少配制酚酞试剂酒精中的含水量，同时也必须降低测试环境湿度。

5.Phenolphthalein: This chemical is an organic dye that is toxic in large quantities.

酚酞：这个化学药品是一个有机染料，大剂量是有毒的。

6.In order to increase reliability using phenolphthalein solution to detect alkaline cell sealing characteristics, the water in the alcohol was decreased, environment humidity were requisite.

为了提高酚酞溶液检测碱性电池密封性能的可靠性，就必须减少配制酚酞试剂酒精中的含水量，同时也必须降低测试环境湿度。

7.Phenolphthalein diphosphate tetrasodium salt hydrate; CAS…

询价酚酞二磷酸四钠水合物；

8.The causes of producing error results were analyzed at detecting alkaline cell seal characteristics, using phenolphthalein solution.

分析了用酚酞试剂检测碱性电池密封性能产生错误结果的原因。

9.The colored solidified alcohol has been prepared by utilizing alcohol, stearic acid, sodium hydroxide, phenolphthalein, copper nitrate and cobalt nitrate.

运用酒精、硬脂酸、氢氧化钠、酚酞、硝酸铜、硝酸钴等原料，制备彩色固体酒精。

10.The laboratory manual suggested using phenolphthalein for acid-base titrations.

实验室手册建议在酸碱滴定中使用酚酞。

11.When the pH reached 8.2, the phenolphthalein turned pink.

当pH值达到8.2时，酚酞变成了粉红色。

12.We added a few drops of phenolphthalein to the solution to check for neutralization.

我们向溶液中添加了几滴酚酞以检查中和反应。

13.The titration process was monitored using phenolphthalein as an indicator.

滴定过程使用酚酞作为指示剂进行监测。

14.In the chemistry lab, we used phenolphthalein to determine the acidity of the solution.

在化学实验室，我们使用酚酞来确定溶液的酸度。

作文

In the realm of chemistry, indicators play a crucial role in determining the pH level of a solution. One of the most widely used indicators is phenolphthalein, a compound that has been instrumental in various titration processes. Understanding phenolphthalein not only enhances our knowledge of acid-base reactions but also provides insight into practical applications in laboratories and industries. Phenolphthalein is a synthetic organic compound that is colorless in acidic solutions and turns pink in basic solutions, making it an effective pH indicator. Its chemical formula is C20H14O4, and it belongs to a class of compounds known as phthaleins. The transition of phenolphthalein from colorless to pink occurs at a pH range of about 8.2 to 10.0, which is particularly useful for detecting the endpoint of titrations involving strong bases. The significance of phenolphthalein extends beyond mere laboratory use; it serves as a vital tool in various fields such as medicine, environmental science, and education. In medical laboratories, phenolphthalein can be used to test the acidity of bodily fluids, helping in the diagnosis of certain conditions. For instance, abnormal levels of acidity in urine can indicate metabolic disorders or infections. Similarly, environmental scientists utilize phenolphthalein to assess the pH of soil and water samples, which is crucial for understanding ecosystem health and pollution levels. In educational settings, phenolphthalein is often introduced to students during chemistry experiments to illustrate the concept of acid-base indicators. The visual change from colorless to pink captures the attention of students and helps them grasp the underlying principles of pH and chemical reactions. This hands-on experience not only reinforces theoretical knowledge but also fosters a deeper appreciation for the subject of chemistry. Despite its many benefits, it is essential to handle phenolphthalein with care, as it can be toxic if ingested or absorbed through the skin. Safety precautions, such as wearing gloves and goggles, should always be observed when working with this compound. Furthermore, while phenolphthalein is an excellent indicator for many applications, it is not universally applicable. For example, it may not be suitable for titrations involving weak acids and weak bases, where more appropriate indicators must be chosen. In conclusion, phenolphthalein is a remarkable chemical compound that serves as a vital indicator in various scientific fields. Its ability to visually signal changes in pH makes it an indispensable tool in laboratories, medical diagnostics, and educational environments. By understanding the properties and applications of phenolphthalein, we gain valuable insights into the world of chemistry and its relevance to our daily lives. As we continue to explore the complexities of chemical reactions, phenolphthalein stands out as a symbol of the intersection between theory and practical application, reminding us of the beauty and utility of science in understanding the world around us.

在化学领域，指示剂在确定溶液的pH值方面发挥着至关重要的作用。其中一种最广泛使用的指示剂是酚酞，这种化合物在各种滴定过程中发挥了重要作用。理解酚酞不仅增强了我们对酸碱反应的知识，还提供了对实验室和工业中实际应用的深入了解。酚酞是一种合成有机化合物，在酸性溶液中无色，而在碱性溶液中则变为粉红色，这使其成为一种有效的pH指示剂。它的化学式为C20H14O4，属于一种称为酞烯的化合物。酚酞从无色变为粉红色的转变发生在大约pH范围为8.2到10.0，这在检测强碱滴定的终点时特别有用。酚酞的重要性超出了实验室的简单使用；它在医学、环境科学和教育等多个领域中都是一种重要工具。在医学实验室中，酚酞可用于测试体液的酸度，有助于某些疾病的诊断。例如，尿液中的异常酸度水平可能表明代谢紊乱或感染。同样，环境科学家利用酚酞来评估土壤和水样本的pH值，这对于了解生态系统健康和污染水平至关重要。在教育环境中，酚酞通常在化学实验中介绍给学生，以说明酸碱指示剂的概念。从无色变为粉红色的视觉变化吸引了学生的注意力，并帮助他们掌握pH和化学反应的基本原理。这种动手实践不仅强化了理论知识，还培养了对化学学科的更深层次的欣赏。尽管有许多好处，但处理酚酞时必须小心，因为如果摄入或通过皮肤吸收，它可能是有毒的。在处理这种化合物时，始终应遵循安全预防措施，例如佩戴手套和护目镜。此外，虽然酚酞在许多应用中是一个很好的指示剂，但并不是普遍适用的。例如，它可能不适合弱酸和弱碱的滴定，此时必须选择更合适的指示剂。总之，酚酞是一种出色的化学化合物，在各个科学领域中作为重要的指示剂。它能够在pH值变化时进行可视信号显示，使其成为实验室、医学诊断和教育环境中不可或缺的工具。通过理解酚酞的性质和应用，我们获得了对化学世界及其与我们日常生活相关性的宝贵见解。当我们继续探索化学反应的复杂性时，酚酞作为理论与实际应用交汇的象征，提醒我们科学在理解周围世界中的美丽和实用性。