Total alkalinity of circulating water
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May I ask why methyl red-bromocresol green is used as an indicator for the total alkalinity of circulating water? What other differences are there between methyl red-bromocresol green and methyl orange, aside from their color change ranges? Thank you.
The color change range using methyl red-bromocresol green as an indicator is 5.0–5.2. Narrow color range, more accurate
This post was last edited by qugd on 2017-9-2 08:57. Mixed acid-base indicators have a narrow color change range, allowing for sharp detection by the human eye. The color change range of methyl red-bromocresol green is from red to green, making it very easy to observe. The color change range of methyl orange is from red to orange-yellow, which can be somewhat difficult to detect with the naked eye for those without experience. https://gss0.baidu.com/-fo3dSag_xI4khGko9WTAnF6hhy/zhidao/pic/item/77c6a7efce1b9d167334516bf1deb48f8d5464cd.jpg It is more accurate to use a pH meter to indicate the end point during the titration process, as this prevents confusion caused by color changes.