The number of electrons that are involved in the reduction of permanganate to manganese (II) salt, manganate and manganese dioxide respectively are

Options

A. `5,1,3`
B. `5,3,1`
C. `2,7,1`
D. `5,2,3`

Answer

A

Explanation

Permanganate ion is `MnO _(4) ^(-).`
(i) Conversion of permanganate into
manganese (II)salt.
`MnO _(4) ^(-) to Mn ^(2+)`
`x + (-2) 4 =-1 + 2`
`x = + 7`
Change in number of electrons `=7-2 =5`
(ii) Conversino of peramagnete into manganate
`MnO _4 ^(-) to Mn O _(4) ^(2-)`
`x + (-2) 4 =01 x (-2) 4=-2`
`x =+ 7 x =+6`
Change in number of electron `=7-6 =1 `
(iii) Conversionof permanganate into manganese dioxide `(MnO _(2))`
`Mn O (4) ^(-) to Mn ^(2+) O _(2)`
`x + (-2 ) 4 =-1 x + (-2) 2=0`
`x = + 7 x - 4 =0 x = + 4`
Change in number of electrons `= 7 - 4=3`
Thus, the number of electrons involved in the given reduction processes are respectively `5,1,3.`