Tollen's reagent is used for the detection of aldehyde. When a solution of $AgNO_3$ is added to glucose with $NH_4OH$,gluconic acid is formed.
$Ag^{+} + e^{-} \rightarrow Ag ; E^{\circ}_{red} = 0.8 \ V$
$C_6H_{12}O_6 + H_2O \rightarrow C_6H_{12}O_7 + 2H^{+} + 2e^{-} ; E^{\circ}_{oxd} = -0.05 \ V$
$Ag(NH_3)_2^{+} + e^{-} \rightarrow Ag_{(s)} + 2NH_3 ; E^{\circ}_{red} = 0.337 \ V$
[Use $2.303 \times \frac{RT}{F} = 0.0592$ and $\frac{F}{RT} = 38.92$ at $298 \ K$]
$1.$ $2Ag^{+} + C_6H_{12}O_6 + H_2O \rightarrow 2Ag_{(s)} + C_6H_{12}O_7 + 2H^{+}$. Find $\ln K$ of this reaction.
$(A) \ 66.13 \quad (B) \ 58.38 \quad (C) \ 28.30 \quad (D) \ 46.29$
$2.$ When ammonia is added to the solution,$pH$ is raised to $11$. Which half-cell reaction is affected by $pH$ and by how much?
$(A) E_{oxd}$ will increase by a factor of $0.65 \ V$ from $E^{\circ}_{oxd}$
$(B) E_{oxd}$ will decrease by a factor of $0.65 \ V$ from $E^{\circ}_{oxd}$
$(C) E_{red}$ will increase by a factor of $0.65 \ V$ from $E^{\circ}_{red}$
$(D) E_{red}$ will decrease by a factor of $0.65 \ V$ from $E^{\circ}_{red}$
$3.$ Ammonia is always added in this reaction. Which of the following must be incorrect?
$(A) NH_3$ combines with $Ag^{+}$ to form a complex.
$(B) Ag(NH_3)_2^{+}$ is a stronger oxidising reagent than $Ag^{+}$.
$(C)$ In absence of $NH_3$,silver salt of gluconic acid is formed.
$(D) NH_3$ has affected the standard reduction potential of glucose/gluconic acid electrode.
Give the answer for questions $1, 2$ and $3$.

• A
  $B, D, C$
• B
  $C, A, D$
• C
  $D, A, B$
• D
  $B, A, D$