Question

Consider the cell `|{:(H_(2)(Pt)),(1atm):} :|: {:(H_(3)O^(+)(aq)),(pH =5.5):}:||{:(Ag^(+)),(xM):}:|Ag` . The measured `EMF` of the cell is `1.023 V`. What is the value of `x`?
`E_(Ag^(+),Ag)^(@) +0.799 V.[T = 25^(@)C]`
A. `2 xx 10^(-2)M`
B. `2 xx 10^(-3)M`
C. `1.5 xx 10^(-3)M`
D. `1.5 xx 10^(-2)M`

Answer 1

Correct Answer - A
`2 Ag^(+) +H_(2) rarr 2H^(+) +2Ag`
`1.023 =(E_(c)-E_(A)) -(0.0591)/(2)log.([H^(+)]^(2))/(P_(H_(2)[Ag^(+)]^(2)))`
`1.023 = 0.799-0 -(0.591 xx2)/(2)log.[H]^(+) +(0.591 xx 2)/(2) log[X]^(2)`
`0.294 = 0.06 xx 5.5 +(0.06)/(2)log(X]^(2)-0.036 =0.03 log_(10)[X]^(2)`
`-0.036 =0.6 log_(10)[X] 0.6 = log_(10)[X]`