For the reaction
`M^(x+)+MnO_(4)^(-)rarrMO_(3)^(-)+Mn^(2+)+(1//2)O_(2)`
if `1 "mol of" MnO_(4)^(-)` oxidises `1.67 "mol of" M^(x+) "to" MO_(3)^(-)`, then the value of `x` in the reaction is

Options

A. 5
B. 3
C. 2
D. 1

Answer

C

Explanation

`overset(+7)(MnO_(4)^(-))+5e^(-)rarrMn^(2+)`
1 mole of `MnO_(4)^(-)` accepts five moles of electrons
`:. 1.67` moles of `M^(x+)` loose five moles of electrons
`:.` Loss of electrons by 1 mole of
`M^(x+)=(5)/(1.67)~~3`
`overset(+x)(M^(x))rarroverset(+5)(MO_(3)^(-))+n e^(-)`
`x=5-n`
But `x=3`
`:. 3=5-n`
or `n=2`.