Electrochemistry

Tollen's reagent is used for the detection of aldehyde when a solution of $\mathrm{AgNO}_3$ is added to glucose with $\mathrm{NH}_4 \mathrm{OH}$ then gluconic acid is formed.

$$ \begin{array}{r} \mathrm{Ag}^{+}+e^{-} \rightarrow \mathrm{Ag} ; \quad \mathrm{E}_{\text {red }}^{\mathrm{o}}=0.8 \mathrm{~V} \\ \mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6+\mathrm{H}_2 \mathrm{O} \rightarrow \text { Gluconic acid }\left(\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_7\right) +2 \mathrm{H}^{+}+2 e ; \\ \mathrm{E}_{\text {oxd }}^{\mathrm{o}}=-0.05 \mathrm{~V} \\ \mathrm{Ag}\left(\mathrm{NH}_3\right)_2^{+}+e^{-} \rightarrow \mathrm{Ag}(\mathrm{~s})+2 \mathrm{NH}_3 ; \\ \mathrm{E}_{\text {red }}^{\mathrm{o}}=0.337 \mathrm{~V} \end{array} $$

[Use $2.303 \times \frac{\text { RT }}{\text { F }}=0.0592$ and

\(\left.\frac{\mathrm{F}}{\mathrm{RT}}=38.92 \text { at } 298 \mathrm{~K}\right]\)

Ammonia is always added in this reaction. Which of the following must be incorrect?