Sodium sulphite `(Na_(2)SO_(3))` is added to meat as a preservative. The presence of `Na_(2)SO_(4)` can be detected by adding dil. `H_(2)SO_(4)` when the pungent smelling gas evolved turns the lime water milky. The gas evolved was detected as sulphur dioxide. The `SO_(2) " to "SO_(4)^(2-)` in titration.
`SO_(2)+2H_(2)O+I_(2) to 4H^(+)+SO_(4)^(2-)+2I^(-)`
In order to check the results of titration, excess barium chloride is added to the final solution. The resulting precipitate is collected and weighed.
Q. `SO_(2) and CO_(2)` both lime water milky. Which of the following reagent can be used to distinguish these two gases?
(I)`K_(2)Cr_(2)O_(7)"/"H_(2)SO_(4)` (II)`KMnO_(4)"/"H^(+)` (III)`I_(2)` solution

Options

A. I, II, III correct
B. I. III only correct
C. II, III only correct
D. III only correct

Answer

A