Volume of `0.1M K_(2)Cr_(2)O_(7)` required to oxidise `35 mL` of `0.5M FeSO_(4)` solution is

Options

A. `29.2 mL`
B. `17.5mL`
C. `175 mL`
D. `145 mL`

Answer

A

Explanation

`Cr_(2)O_(7)^(2-)+14H^(+)+6e^(-)rarr 2Cr^(3+)+7H_(2)O`
`Fe^(2+)rarr Fe^(3+)+e^(-)xx6`
`Cr_(2)O_(7)^(2-)+6Fe^(2+)+14H^(+)rarr 2Cr^(3+)+7H_(2)O+6Fe^(3+)`
`(M_(1)V_(1))/(n_(1))=(M_(2)V_(2))/(n_(2))`
`(Cr_(2)O_(7)^(2-)) ( Fe^(2+))`
`(0.1xxV_(1))/(1)=(0.5xx35)/(6)`
`V_(1)=(5xx35)/(6)=29.17 mL`