The reduction potential ofhydrogen half-cell will be negative if:

Options

A. `p(H_(2))=1` atm and `[H^(+)]=2.0M`
B. `p(H_(2)) =1` atmand `[H^(+)] =1.01M`
C. `p (H_(2)) =2` atm and `[H^(2)]=1.0M`
D. `p(H_(3))=2` atm and `[H^(+)]=2.0M`

Answer

C

Explanation

`H^(+) +e ^(-) to 1/2 H_(2)`
`E =E^(@) =(0.059)/(1) log ""([P (H_(2))]^(1//2))/([H^(+)])`
Now if`PH_(2)=2` atm and `[H^(+)]=lM`
then `E= 0- (0.059)/(1) log""(2^(1//2))/(1) =(-0.059)/(2) log 2`