新型便捷式碱式滴定管的研制与应用
Fabrication and Application of a New Convenient Base Buret
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摘要: 研制了一种新颖的便捷碱式滴定管。将普通碱式滴定管的橡胶管以下部分用聚四氟乙烯塑料铸件代替,此铸件将滴液栓及滴定尖嘴等组件集合于一体,在结构上不与滴定管连在一起,组装时将玻璃滴定管下端插入并固定在铸件上部的凹槽内。应用此改进的碱式滴定管做氢氧化钠溶液的标定试验,连续进行5次滴定,计算得其相对标准偏差为0.03%,而用普通碱式滴定管操作时,所得相对标准偏差为0.72%。由此说明使用便捷式碱式滴定管不仅克服了普通滴定管的缺点,而且可获得更好的精密度。Abstract: A new convenient base buret was fabricated by replacing the lower part (including the rubber tubing-glass bead stop-coak and the dropping glass tip) of the common base buret by a PTFE casting which aggregate the functions of stopcock and dropping tip and it was designed to be separated from the glass buret tube. In installing the apparatus, lower end of the buret tube was inserted into the concave channel of the casting and fixed in it. The modified convenient base buret was applied to the standardization of NaOH solution. Five successive titrations were made, giving value of RSD 0.03% which was much better than the value of RSD (0.72%) obtained by using the common base buret. It was proved that not only the short-comings of common base buret were overcome by using the modified base buret, but also the precision of titration was much improved.