Asample of an alloy weighing `0.50 g` and containing 90% Ag was dissolved in conc. `HNO_(3)`. Ag was analysed by Volhard method in which 25mL of KCNS were required for complete neutralization. Determine normality of KCNS.

Options

A. `0.167`
B. `0.326`
C. `0.267`
D. `0.067`

Answer

A

Explanation

Mass of `Ag = ( 90 xx 0. 5)/( 100) = 0. 45`
`therefore ` Meq, of `A g = ( 90 xx 0. 5)/(100) = 0. 45 xx 1000 = 4. 17`
Now, `Ag overset(HNO _(3)) to A g NO _(3) overset(KCNS)to Ag CNS`
`therefore` Meq. Of KCNS = Meq. Of `Ag NO _(3)`
= Meq. of `HNO _(3) = Meq.` of Ag
`therefore N xx 25 = 4. 17 therefore N = 0 . 167`