List of top Chemistry Questions on Electrochemistry

Which of the following statements are correct about a dry cell?

• [(I)] It is also known as Leclanche cell.

• [(II)] Electrolyte is a moist paste of \(NH_4Cl\) and \(ZnCl_2\).

• [(III)] Reaction at cathode is \[ MnO_2 + NH_4^+ + e^- \rightarrow MnO(OH) + NH_3 \]

• [(IV)] It can be charged.
A student builds a galvanic cell utilizing the reaction \[ Ni(s)+2Ag^+(aq)\rightarrow Ni^{2+}(aq)+2Ag(s) \] \[ E^\circ=1.05V \] At \(25^\circ C\), what could the student do for the cell to generate a potential greater than that of the initial standard cell?
How many faradays of electricity are required to produce $12\,\mathrm{g}$ of magnesium from molten $\mathrm{MgCl_2}$?} \[ (\text{Atomic weight of Mg}=24\,\mathrm{g\,mol^{-1}}) \]
The following reaction takes place in a galvanic cell at \(298\) K \[ \mathrm{Fe^{2+}(aq)+Ag^+(aq)\rightarrow Fe^{3+}(aq)+Ag(s)} \] The \(\Delta_rG^\circ\) (in kJ mol\(^{-1}\)) and \(\log K_c\) values are respectively \[ (F=96500\ \mathrm{C\,mol^{-1}},\; E^\circ_{\mathrm{Ag^+/Ag}}=0.80\ \mathrm{V},\; E^\circ_{\mathrm{Fe^{3+}/Fe^{2+}}}=0.77\ \mathrm{V},\; R=8.3\ \mathrm{J\,mol^{-1}K^{-1}}) \]
The following reaction takes place in a galvanic cell \[ 2Cr(s)+3Cd^{2+}(aq)\rightarrow2Cr^{3+}(aq)+3Cd(s) \] What is \(\Delta_rG^\circ\) of this cell? Given: \[ F=96500~Cmol^{-1} \] \[ E_{Cd^{2+}/Cd}^{\circ}=-0.4V \] \[ E_{Cr^{3+}/Cr}^{\circ}=-0.74V \]
The order of negative standard potential values of \(\text{Li}\), \(\text{Na}\), \(\text{K}\) is
Three electrolytic cells P, Q and R containing aqueous solutions of \(Al(NO_3)_3\), \(AgNO_3\) and \(CuSO_4\) respectively are connected in series. A current of 1.5 A was passed until 1.45 g of Ag was deposited. Find the masses of Al and Cu deposited.
Which of the following reactions occurs at cathode during recharging of lead accumulator ?
If standard reduction potential of four electrodes A, B, C, D are \(+2.5\,\text{V},+3.0\,\text{V},-2.0\,\text{V}\) and \(-1.5\,\text{V}\) respectively. When is the standard emf of cell maximum?
What happens during the discharge of a lead storage battery?
Which of the following is an electrolyte in dry cell ?
Which from following statements regarding mercury battery is NOT true?
Identify from following cell reactions that is spontaneous under standard state of conditions.
The most active metal among the following is:
What will be the Nernst equation of the cell for the following reaction?
\( 2Cr(s) + 3Cd^{2+}(aq) \rightarrow 2Cr^{3+}(aq) + 3Cd(s) \)
i) Define standard electrode potential. (1)
ii) Define bidentate ligand. (1)
iii) Complete the following reactions (1+1+1):
a) RX + NaOR' → ?
b) C6H5COCH3 (acetophenone) + H2/Pd-BaSO4 → ?
c) C6H6 (benzene) + CO + HCl → (AlCl3/Cu2Cl2) ?
OR
i) Explain standard hydrogen electrode potential with diagram. (1)
ii) Give an example of optical isomerism. (1)
iii) Complete the following reactions (1+1+1):
a) CH3CH2OH → (H2SO4, 413 K) ?
b) RCN + SnCl2 + HCl → ?
c) C6H5CH3 (toluene) + CrO2Cl2 + CS2 → ?
The pH and conductance of a weak acid (HX) was found to be 5 and \(4\times10^{-5}\) S, respectively. The conductance was measured under standard condition using a cell where the electrode plates having a surface area of 1 cm\(^2\) were at a distance of 15 cm apart. The value of the limiting molar conductivity (\(\Lambda_m^\circ\)) is___ S cm\(^2\) mol\(^{-1}\) (nearest integer) (Given: degree of dissociation \(\alpha \ll 1\))
  
The conductivity of $0.1$ mol $L^{-1}$ solution of NaCl is $1.06 \times 10^{-2}$ S $cm^{-1}$. Calculate its molar conductivity and degree of dissociation. ($\lambda^\circ_{Na^+} = 50.1, \lambda^\circ_{Cl^-} = 76.5$ S $cm^2$ $mol^{-1}$). (b) (i) Predict current flow direction for $2Ag^+ + Zn \rightarrow 2Ag + Zn^{2+}$. (ii) Differentiate between primary and secondary battery.
The standard electrode potentials of three metals A, B and C are, respectively, + 0.34 V, - 1.18 V and - 0.25 V. The correct order of reducing power of these metals is :
Which of the following electrolytic solutions of the same electrolyte has maximum electrolytic conductivity at the same temperature?
The electrolyte used in $H_2 - O_2$ fuel cell is ________.
An aqueous solution of CuSO$_4$ solution is electrolysed for 193 s with a current of 2.5 amp. Given that the atomic mass of Cu is 63.5 and F = 96500 coulombs, the amount of copper deposited at the anode is
Explain electrode potential and standard electrode potential. The following reaction takes place in a cell: \[ \text{Zn(s)} + \text{Co}^{2+} \rightleftharpoons \text{Co(s)} + \text{Zn}^{2+} \] Calculate the standard cell potential \(E^\circ_{cell}\) of the cell. Given: \(E^\circ_{(\text{Zn} \rightarrow \text{Zn}^{2+})} = 0.76\,\text{V}\) and \(E^\circ_{(\text{Co} \rightarrow \text{Co}^{2+})} = 0.28\,\text{V}\) (oxidation potentials).
Is the following reaction possible or not? Explain with reasons. \[Zn(NO_3)_2 + 2Ag \rightarrow 2AgNO_3 + Zn\]
In which cell does the following reaction take place? \[2H_2(g) + O_2(g) \rightarrow 2H_2O(l)\]