近來有同仁問到,“一定濃度的堿性乙醇/甲醇怎么配制?一定濃度的氫氧化鉀乙醇/甲醇溶液怎么配制?乙醇制氫氧化鉀滴定液怎么配制?”。幾個問題其實歸結起來也就是一個問題“一定濃度乙醇制氫氧化鉀滴定液怎么配制?”,弄清這點之后,類似堿醇溶液的配制方法便可輕松搞定。
Recently, a colleague asked, "how to prepare a certain concentration of basic ethanol / methanol? How to prepare a certain concentration of potassium hydroxide ethanol / methanol solution? How to prepare potassium hydroxide titrant from ethanol. In fact, several problems can be summed up as "how to prepare potassium hydroxide titrant with a certain concentration of ethanol?", After understanding this point, the preparation method similar to alkali alcohol solution can be easily done.
氫氧化鉀生產廠家現將乙醇制氫氧化鉀滴定液(0.5mol/L或0.lmol/L)和甲醇制氫氧化鉀滴定液(0.lmol/L)的配制和標定方法分享給大家。
Potassium hydroxide manufacturers now share the preparation and calibration methods of potassium hydroxide titrant (0.5mol/l or 0.lmol/l) made from ethanol and potassium hydroxide titrant (0.lmol/l) made from methanol.
從氫氧化鉀生產廠家介紹的配制過程來看,配制過程中,取用的氫氧化鉀量較理論量略大,之所以這樣做,是因為氫氧化鉀本身在乙醇中的溶解度很大,但是氫氧化鉀在空氣中會吸收二氧化碳,而且氫氧化鉀吸水能力也很強,再者配制好的堿醇溶液同樣會吸收空氣和溶液中的二氧化碳而消耗溶液中的堿。
According to the preparation process introduced by the potassium hydroxide manufacturer, the amount of potassium hydroxide used in the preparation process is slightly larger than the theoretical amount. The reason for this is that the solubility of potassium hydroxide itself in ethanol is very high, but potassium hydroxide will absorb carbon dioxide in the air, and the water absorption capacity of potassium hydroxide is also very strong, Moreover, the prepared alkali alcohol solution will also absorb the air and carbon dioxide in the solution and consume the alkali in the solution.
基于以上考慮,配制過程中應多稱一些氫氧化鉀才能達到需要的堿濃度,但是很難定向配制到具體的濃度,所以氫氧化鉀生產廠家配制的堿醇溶液臨用前應標定濃度,然后通過換算得到具體的堿濃度。
Based on the above considerations, more potassium hydroxide should be weighed in the preparation process to achieve the required alkali concentration, but it is difficult to prepare the specific concentration directionally. Therefore, the alkali alcohol solution prepared by potassium hydroxide manufacturers should calibrate the concentration before use, and then obtain the specific alkali concentration through conversion.