In the reaction of sodium thiosulphate with `I_(2)` in aqueous medium, the equivalent mass of sodium sulphate

Options

A. Molar mass of sodium thiosulphate
B. The average of molar masses of `Na_(2)S_(2)O_(3)` and `I_(2)`
C. Half the molar mass of sodium thiosulphate
D. Molar mass of sodium thiosulphate `xx` 2

Answer

A

Explanation

`2Na_(2)S_(2)O_(3).5H_(2)O +I_(2) to 2NaI + Na_(2)S_(4)O_(6)` or `2S_(2)O_(3)^(-2) to S_(4)O_(5)^(2-) + 2e^(-)`
Equivalent weight of `Na_(2)S_(2)O_(3).5H_(2)O`
` = ("Mol.wt")/(1) = (248)/(1) = 248`