2.2.1. Standard phosphate solution [4]
A weighed amount, 0.2077 g of sodium dihydrogen phosphate
dihydrate was transferred into a clean beaker. It was dissolved in
water and the solution was transferred into a 250 ml volumetric
flask and diluted to the mark with water [4]. The working
5.3×10−4M phosphate solution was prepared by its further dilution.