How to standardise `Na_(2)S_(2)O_(3)` solution in iodometry? – InterviewSolution

InterviewSolution

1.	How to standardise `Na_(2)S_(2)O_(3)` solution in iodometry?
Answer» `K_(2)Cr_(2)O_(7)` is primary standard `rArr" "` strength is know by weighing the salt in chemical balance and dissolving in measured amount of water. Then in acidic solution add. `KI` `Cr_(2)O_(7)""^(2-)+14H^(+)+6I^(-)to2Cr^(3+)+3I_(2)+7H_(2)O` This `I_(2)` is liberated can be estimated with `S_(2)O_(3)""^(2-)`.

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