Potassium iodide GB/T 1272-2007
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Dear experts, in GB/T 1272-2007 for potassium iodide, the criteria for determining the end point of titration are rather unclear and difficult to judge. Those with experience, please provide some guidance
In the GB/T 1272-2007 standard for \"Potassium iodide\", titration is commonly used for content determination. The determination of the endpoint can indeed be somewhat ambiguous; generally, it involves observing the change in color of the titrant as it shifts from one color to another. It is recommended to use the correct indicator, such as starch indicator, and to follow the procedure carefully; additionally, conducting multiple experiments will help improve experience and the accuracy of judgment. During the experiment, ensure there is sufficient light and pay close attention to subtle changes in color. .
This post was last edited by qqgd on 2024-9-4 09:15. When using the iodometry method for titration, it is necessary to observe the endpoint with the naked eye; one needs to practice several times, and it is also advisable to carefully compare the color changes before and after the endpoint. Manual titration requires experience; one needs to practice it many times – there are no shortcuts. Or consult experienced masters for advice. You can also assemble your own dead-stop end indicator; using changes in current to indicate the end point is also an option
The indicator required by the standard, namely sodium eosin solution, becomes turbid very quickly at the start of titration, with tiny white particles forming. Due to the presence of this indicator, the solution remains pink throughout, making it extremely difficult to determine the endpoint