Study on the Effect of Appearance of the Primary Standard on Standardizing the Standard Solution: Borax as an Example

: Borax in different appearance is compared and studied in standardization of the standard hydrochloric acid as primary standard. The obtained concentrations of hydrochloric acid are 0.1049 mol∙L −1 and 0.1052 mol∙L −1 , respectively. Then based on the statistical test of the data, it was revealed that there are significant differences between the two. Additionally, appearance differences of borax, which may be caused by the change of its properties, will give rise to the error of subsequent measurements.