Bleaching powder and bleach solution are produced on a large scale and used in several hous-hold products. The effectiveness of bleach solution id often measured by iodometry.
`25 mL` of household bleach solution was mixed with `30 mL` of `0.50 M KI` and `10 mL` of `4N` acetic acid. In the titration of the liberated iodine, `48 mL` of `0.25 N Na_(2)S_(2)O_(3)` was used to reach the end point. The molarity of the household bleach solution is :

Options

A. `0.48 M`
B. `0.96 M`
C. `0.24 M`
D. `0.24 M`

Answer

C

Explanation

`2CH_(3)COOH+CaOCl_(2)rarr(CH_(3)COO)_(2)Ca+H_(2)O+Cl_(2)`
`2KI+Cl_(2)rarr2KCl+I_(2)`
`2Na_(2)S_(2)O_(3)+I_(2)rarrNa_(2)S_(4)O_(6)+2NaI`
`1` milli-mole of `CaOCl_(2)=(1)/(2)xx0.25xx48=6`
`"Molarity"xx"volume"=6 "milli-moles"`
`"Molarity"=(6)/(25)=0.24M`