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

Options

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

Answer

C

Explanation

`2H_((aq.))^(+)+2e^(-)rarrH_(2(g))`
`E_(RP)=E_(RP)^(0)-(0.059)/(n)log.(P_(H_(2)))/([H^(+)])`
`=0-(0.059)/(2)log.(2)/(1^(2))` will only be negative when `P_(H_(2))gt[H^(+)]`