To a 25 mL `H_(2)O_(2)` solution excess of an acidified solution of potassium iodide was added. The iodine liberated required 20 " mL of " 0.3 N sodium thiosulphate solution Calculate the volume strength of `H_(2)O_(2)` solution.

Explanation

m" Eq of "`Na_(2)S_(2)O_(3)=20xx0.3=6`
m" Eq of "`I_(2)=6`
m" Eq of "`KI=6`
m" Eq of "`H_(2)O_(2)=6`
Normality of `H_(2)O_(2)=(6)/(25)`
For `H_(2)O_(2)`,
`5.6xx` Normality`=` volume strength
`therefore` Volume strength`=(6)/(25)xx5.6=1.344`