Question

if the solution of the naoh needs to be diluted for the purpose of standardization with the khp standard, that dilution should be done with a graduated cylinder (quantitative dilution is not required). why?

Answer 1

Dilution of NaOH using a graduated cylinder is acceptable during standardization with KHP because the accuracy of the procedure depends on stoichiometric reaction rather than the precise volume of NaOH solution used.

Step-by-step explanation:

When standardizing a NaOH solution with a potassium hydrogen phthalate (KHP) standard, it's often acceptable to use a graduated cylinder for dilution because the process of standardization is sensitive to the stoichiometry rather than the precise volume of the NaOH solution.

This is due to the fact that during standardization, the chemist will always titrate the NaOH solution to the exact endpoint with the KHP.

An accurate concentration of NaOH is determined by the exact amount of KHP used, which is precisely weighed, and the NaOH volume used to reach the endpoint.

Therefore, the key factor is the stoichiometric reaction between NaOH and KHP, not the exact volume of NaOH put into the flask, which is why a precise volumetric use, like that afforded by a volumetric flask, is not necessary for this part of the procedure.