Hypo is the common name of sodium thiosulphate, with molecular formula `Na_(2)S_(2)O_(3)`. It is used as intermediate in iodometric as well as in iodimetric titrations.
Iodine and chlorine react with hypo in different ways as follows :
`2na_(2)S_(2)O_(3)+I_(2) to 2NaI+Na_(2)S_(4)O_(6)`
`Cl_(2)(g)+S_(2)O_(3)^(2-) to SO_(4)^(2-) + Cl^(-) +S`
Suppose, 50 mL of `0.01 M Na_(2)S_(2)O_(3)` solution and `5xx10^(-4)` mol of `Cl_(2)` are allowed to react according to the above equation. Hypo is also used in photography to dissolve AgBr, forming a complex compound.
`2Na_(2)S_(2)O_(3) +AgBr to Na_(3)[Ag(S_(2)O_(3))_(2)]+NaBr`
The balanced chemical reaction with `Cl_(2)` is :

Options

A. `Cl_(2)+2Na_(2)S_(2)O_(3) to 2NaCl+Na_(2)S_(4)O_(6)`
B. `Cl_(2)+H_(2)O+Na_(2)S_(2)O_(3) to Na_(2)SO_(4)+2HCl+S`
C. `Cl_(2)(g)+S_(2)O_(3)^(2-) to SO_(4)^(2-)+S+Cl^(-)`
D. none of the above

Answer

B