The reduction potential of hydrogen half cell will be negative if :

Options

A. `P_((H_(2)))=1atm" "and [H^(+)]=2.0M`
B. `P_((H_(2)))=1atm and [H^(+)]=1.0M`
C. `P_((H_(2)))=2atm and [H^(+)]=1.0M`
D. `P_((H_(2)))=2atm and [H^+]=2.0M`

Answer

C

Explanation

`2_((aq))^(+)+2e^(-)toH_(2(g))`
`E_(red)=E_(red)^(@)-(0.0591)/(n)log((P_((H_(2))))/((H^(+))^(2))`
`E_(red)=0-(0.0591)/(2)log((2)/((1)^(2))`
`E_(red)=(0.0591)/(2)log2`
`thereforeE_(red)` is found to be negative for (c) option.