The pressure of `H_(2)` required to make the potential of `H_(2^(-))` electrode zero in pure water at `298 K` is

Options

A. `10^(4) atm`
B. `10^(-14) atm`
C. `10^(12) atm`
D. `10^(-10) atm`

Answer

B

Explanation

(b) For water pH=7
`-log[H^(+)]=7" or " [H^(+)]=10^(-17)`
`2H^(+)(aq)+2e^(-) to H_(2)(g)`
`E_(cell)=E_(cell)^(@)-(0.0591)/(2)"log"(pH_(2))/([H^(+)]^(2))`
`0=0-(0.0591)/(2)"log"(pH_(2))/([10^(-7)]^(2))`
`"log"(pH_(2))/([10^(-7)]^(2))=0" or "(pH_(2))/((10^(-7))^(2))=1 " " (`:'` log 1=0)`
or `pH=10^(-14) atm`.