Question

K2Cr2O7 is preferred over Na2Cr2O7 in volumetric analysis though both are oxidising agents. Give reasons

Answer 1

Potassium dichromate is preferred over sodium dichromate in volumetric analysis, primarily because the latter is hygroscopic in nature and, therefore, accurate weighing is not possible in normal atmospheric conditions. A hygroscopic substance absorbs moisture from the atmosphere and this could lead to inaccuracies in weight.