What mass of `N_(2)H_(4)` can be oxidised to `N_(2)` by 24.0 g `K_(2)CrO_(4)`, which is reduced to `Cr(OH)_(4)^(-)` (Given : Molar mass of `K_(2)CrO_(4)=194.2` )

Options

A. 9.97 g
B. 2.97 g
C. 3.97 g
D. 4.97 g

Answer

B

Explanation

`N_(2)^(2-)toN_(2)^(0)+4e`
`Cr^(6)+3etoCr^(3+`
Meq. of `N_(2)H_(4)` =meq. of `K_(2)CrO_(4)`
`(w)/(32//4)xx1000=(24)/(194.2//3)xx1000`
`(E.wt=(Mwt.)/("Valence factor"))`
`W_(N_(2)H_(4))=2.97g`