Kf sadndardization

why was using di sodium titrate for sandardization

Disodium tartrate contains fixed amount of water of crystallisation according to its molecular formula and is available in pure form. Hence, it is considered as a primary standard for standardisation of Karl Fischer reagent. Alternatively, we can try distilled water also for standardisation of KF reagent. Theoretically, 1 mL of KF reagent is equivalent to 5 mg of H2O (water).