4 mole of a mixture of Mohr's salt and `Fe_(2)(SO_(4))_(3)` requires 500mL of `1 M K_(2)Cr_(2)O_(7)` for complete oxidation in acidic medium. The mole % of the Mohr's salt in the mixture is:

Options

A. 25
B. 50
C. 60
D. 75

Answer

D

Explanation

`Cr_(2)O_(7)^(-2)+6Fe^(+2)(n=1)("Mohr's salt")+14H^(+)to2Cr^(+3)+6Fe^(+3)+7H_(2)O`
Equivalent of `Fe^(+2)` = moles of Mohr's salt
`" "`=equivalent of `K_(2)Cr_(2)O_(7)`
`" "=500xx10^(-3)xx6xx1=3`
Hence mole present of Mohr's salt
= `(3)/(4)xx100=75`