The potential of the cell for the reaction `M(s)+2H^(+)(1M)rarrH_(2)(g)(1"atm")+M^(2+)(0.1M)` is 1.500V the standard reduction potential for `M^(2+)//M` couple is

Options

A. 0.1470V
B. 1.470V
C. `-1.47V`
D. none of these

Answer

C

Explanation

The cell is
`M|M^(2+)(0.1M)||H^(+)(M)|H^(+)(M)|H _(2)(1"atm")`
`E_("cell")=E_("cell")^(@)-(0.0591)/(2)"log"[M^(2+)]`
`1.5=E_("cell")^(@)-(0.0591)/(2)"log"(0.1)`
`1.5=E_("cell")^(@)+0.02955`
or `E_("cell")^(@)=E_(2H^(+)//H_(2))^(@)-E_(M^(2+)//M)^(@)`
`therefore 1.47=0-E_(M^(2+)//M)^(@)`
or `E_(M^(2+)//M)^(@)=-1.47V`.