Calculate the equivalent weight of hypo based on its reaction with iodine.

Explanation

Hypo reduces iodine to iodide and the chemical equation is given as
`2Na_(2)S_(2)O_(3)+I_(2)to2NaI +Na_(2)S_(4)O_(6)`
Sum of the oxidation number of .S. in reactions =2 (-2+6) =+8
Sum of the oxidation numberof .S. in products `=4"x"+2.5=+10`
Change in oxidation number of S is 2
Change in oxidation number per mole of sodium thiosulphate =1
Chemical formula of hypo is `Na_(2)S_(2)O_(3) . 5H_(2)O`
Formula weight of hypo = 158+90 =248
Equivalent weight`=("Formula weight")/(1)=248`