For the cell reaction, `Mg(s)+2Ag^(+) (aq.) hArr Mg^(2+) (aq.)+2Ag(s)`
`E_(cell)^(@)` is +3.17 V at 298 K. The value of `E_(cell), Delta G^(@)` and Q at Ag and `Mg^(2+)` concentration of 0.001 M and 0.02 M respectively are :

Options

A. `3.04 V, -605.8 kJ mol^(-1), 20000`
B. `3.04 V, 611.8 kJ mol^(-1), 20000`
C. `3.13 V, -604 kJ mol^(-1), 20`
D. `3.04 V, -611.8 kJ , 20000`

Answer

D

Explanation

`E^(@) = + 3.17V, n = 2`
`Q = ([Mg^(2+)])/([Ag^(+)]^(2)) = (0.02)/([0.001]^(2)) = 20000`
`Delta G^(@) = -nFE^(@)`
`= - 2 xx 96500 xx 3.17`
`= -611.8 kJ`
`E = E^(@) - (0.059)/(n) log_(10)Q`
`= 3.17 - (0.059)/(2) log(20000)`
`= + 3.04 V`