I. On the washing of precipitates
I. On the washing of precipitates
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一、关于沉淀物的洗涤
DOI：
10.1080/14786446908640095
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
R. Bunsen
中科院分区：
文献类型：
--
作者：
R. Bunsen
因此，式(4)得出的结论是，除去沉淀物中所含杂质到沉淀物中的杂质所需的最少流体量，相当于沉淀物本身在其存在的液体中所占体积的11.5倍。因此，很明显，洗涤沉淀物所需的实际水量越接近这一最小值，我们倾倒的频率就越高，每次倾倒时使用的洗涤水量就越少。由于分析工作中的一些主要误差来源在于沉淀物的洗涤不完整或洗涤时间太长，因此了解如何在过程的几个阶段确定洗涤进度变得重要。通过在每次相继加入时使用相同体积的水，并估计其与留在容器底部或过滤器上的沉淀物的关系，我们可以从下表中找到需要倾倒的次数，利用上面给出的公式计算，以将沉淀物中的杂质减少到1.1或1份。第一栏。
1000o0 part.: Making therefore a----lO0000 and v= l, it results from equation (4) that the least quantity of fluid required in order to remove the impurity contained in a precipitate to the} o0000 part, amounts to eleven and a half times the volume occupied by the precipitate itself in the liquid in which it exists. It is evident, therefore, that the amount of water actually necessary to wash a precipitate the more nearly approaches this minimum the oftener we decant, and the smaller the quantity of washing-water we employ at each decantation.Since some of the principal sources of error in analytical work consist in the incomplete or in the too protracted washing of precipitates, it becomes important to know how to ascertain the progress of the washing throughout the several stages of the process. By employing the same volume of water at each successive addition, and estimating its relation to that of the precipitate remaining at the bottom of the vessel or upon the filter, we can find from the following Table, calculated by means of the formula above given, the number of times it is necessary to decant in order to diminish the amount of impm'ity ill the precipitate to the 1 1 1 or 1 part. Column I.