[" The primary standard solution for estimation "],[" of "Na_(2)S_(2)O_(3)" is "]

Na_(2)S_(2)O_(3) is prepared by :

Na_(2)S_(2)O_(3) is prepared by :

In volumetric analysis, why is K_(2)Cr_(2)O_(7) used to prepare the standard solution and not Na_(2)Cr_(2)O_(7) ?

The density of 3 M solution of sodium thiosulphate (Na_(2)S_(2)O_(3)) is 1.25 g/mL. Calculate molality of Na^(+) " and "S_(2)O_(3)""^(2-) ions

A standard solution of K_(2)Cr_(2)O_(7) (mol. Mass 294) contains 2.94 g dissolved to make 250 ml solution 20 ml of this solution with excess of 5% Kl solution liberate iodine which when titrated with Na_(2)S_(2)O_(3) solutioin using starch indicator changes blue colour to colourless just at the addition of 18 ml Na_(2)S_(2)O_(3) solution. The average oxidation number of sulphur in the product of titration and the molarity of Na_(2)S_(2)O_(3) are

S_(8)+NaOH to Na_(2)S+Na_(2)S_(2)O_(3)