Tollen reagent is used for the detection of aldehydes. When a solution of `AgNO_(3)` is added to glucose with `NH_(4)OH`, then gluconic acid is formed.
`Ag^(o+)+e^(-) rarr Ag," "E^(c-)._(red)=0.8V`
`C_(6)H_(12)O_(6)rarr underset(Gluconic aci d)(C_(6)H_(12)O_(7)+)2H^(o+)+2e^(-) , " "E^(c-)._(o x i d ) =-0.05V`
`[Ag(NH_(3))_(2)]^(o+)+e^(-) rarr Ag(s)+2NH_(3), " "E^(c-)._(red)=0.337V`
`[Use2.303xx(RT)/(F)=0.0592` and `(F)/(RT)=38.92at 298 K ]`
`2Ag^(o+)+C_(6)H^(12)O_(6)+H_(2)O rarr 2Ag^(s)+C_(6)H_(12)O_(7)+2H^(o+)` Find `lnK` of this reaction.

Answer

b

Explanation

Cell reaction `:`
`i. Ag^(o+)+e^(-) rarr Ag(s)," "E^(c-)._(red)=0.8V`
`ii. C_(6)H_(12)O_(6)rarr C_(6)H_(12)O_(7)+2H^(o+)+2e^(-), " "E_(o x i d)=-0.05V`
Hence, for reaction
`2Ag^(o+)+C_(6)H_(12)O_(6)+H_(2)Orarr 2Ag(s)+C_(6)H_(12)O_(7)+2H^(o+)`
`E^(c-)._(cell)=0.8-0.05`
`=0.75V`
`E_(cell)=E^(c-)._(cell)-(2.303)/(nF)log K`
At equilibrium, `E_(cell)=0`
`:. E^(c-)._(cell)=(2.303RT)/(nF)log K`
`0.75=(0.0592)/(2) log K`
`log K =(2xx0.75)/(0.0592)=25.33`
or `ln K =2.303xxlogk`
`=2.303xx25.33`
`=58.35`