Tollen’s reagent is used for the detection of aldehydes. When a solution of AgNO 3 is…
Chemistry · JEE Advanced · NTA Exams — Electrochemistry
Tollen’s reagent is used for the detection of aldehydes. When a solution of AgNO3 is added to glucose with NH4OH, then gluconic acid is formed.
Ag+ + e– → Ag; \(\mathrm{E}_{\mathrm{red}}^{\mathrm{o}}\)= 0.80 V
C6H12O6 + H2O → \(\underset{\text { gluconic acid }}{\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{7}}\)+ 2H+ + 2e–;
\(\mathrm{E}_{\text {oxidation }}^{\mathrm{o}}\) = – 0.05 V
\(\mathrm{Ag}\left(\mathrm{NH}_{3}\right)_{2}^{+}+\mathrm{e}^{-}\)\(\text { → }\) Ag (s) + 2NH3; \(\mathrm{E}_{\mathrm{red}}^{\mathrm{o}}\) = 0.337V
[Use 2.303 × \(\frac{\mathrm{RT}}{\mathrm{~F}}\)= 0.0592 and \(\frac{\mathrm{F}}{\mathrm{RT}}\) = 38.92 at 298 K]
(2006)
Ammonia is always added in this reaction. Which of the following must be incorrect ?
- NH3 combines with Ag+ to form a complex
- Ag(NH3)+2 is a stronger oxidising reagent than Ag+
- In absence of NH3 silver salt of gluconic acid is formed
- NH3 has affected the standard reduction potential of glucose/gluconic acid electrode
Answer
(D) NH 3 has affected the standard reduction potential of glucose/gluconic acid electrode
Sign up free on Edukali to view the step-by-step worked solution and practice thousands of similar questions.
Related practice questions
- Standard reduction electrode potentials of three metals A, B and C are respectively – 0.5, – 3.0 V and – 1.2…
- Consider the following cell reaction 2Fe ( s ) + O 2( g ) + 4H + ( aq ) → 2Fe 2 + ( aq ) + 2H 2 O ( l ) ; E°…
- The cell constant of a given cell is 0.47 cm –1 . The resistance of a solution placed in this cell is…
- The electrochemical cell shown below is a concentration cell. M|M 2+ (saturated solution of a sparingly…
- The standard reduction potentials at 298K for the following half reactions are given against each Zn 2+ (aq)…
- Cell reaction for the cell Zn | Zn 2+ (1.0 M) || Cd 2+ (1.0 M) | Cd is given by
- Equivalent conductances of NaCl, HCl and CH 3 COONa at infinite dilution are 126.45, 426.16 and 91 ohm –1 cm…
- Redox reaction play a pivotal role in chemistry and biology. The values of standard redox potential (Eº) of…
More Electrochemistry questions · Browse all practice questions