JEE Electrochemistry PYQs with Solutions PDF, Download Now

For a closed circuit Daniell cell, which of the following plots is the accurate one at a given temperature?

MX is a sparingly soluble salt that follows the given solubility equilibrium at 298 K.
$$MX(s) \rightleftharpoons M^{+} (aq)+X^{-}(aq); K_{sp}=10^{-10}$$
If the standard reduction potential for $$M^{+}(aq)\xrightarrow {+e^{-}}M(s)$$ and $$\left(E_{M^{+}/M}^\ominus\right)=0.79V$$, then the value of the standard reduction potential for the metal/metal insoluble salt electrode $$E^{\ominus}_{X^{-}/MX (s)/M }$$ is __________mV.(nearest integer)
[Given : $$\frac{2.303RT}{F} = 0.059V$$]

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 is ______ S $$m^{2}mol^{-1}$$ (nearest integer)
(Given : degree of dissociation of the weak acid ($$\alpha$$) < < 1)

Consider the following electrochemical cell : $$Pt| O_{2}(g)(1 bar) | HCl(aq)||M^{2+}(aq,1.0M)|M(s)$$
The pH above which , oxygen gas would start to evolve at anode is ____ (nearest integer).
[Given: $$E_{M^{2+}/m}^\circ = 0.994V$$ , $$E_{O^{2}/H_{2}O}^\circ = 1.23V$$ are standard reduction potential and $$\frac{RT}{F}(2.303)=0.059V$$ at the given condition]

In the given electrochemical cell, $$Ag(s)|AgCl(s)|FeCl_{2}(aq),FeCl_{3}(aq)|Pt(s)$$ at298 K, theceU potential $$E_{cell}$$ will increase when:
A. Concentration of $$Fe^{2+}$$ is increased.
B. Concentration of $$Fe^{3+}$$ is decreased.
C. Concentration of $$Fe^{2+}$$ is decreased.
D. Concentration of $$Fe^{3+}$$ is increased.
E. Concentration of $$Cl^{-}$$ is increased.
Choose the correct answer from the options given below :

Consider the following electrochemical cell at 298K

$$ Pt \mid HSnO_2{^-}(aq)\mid Sn(OH)_6{^{2-}}(aq)\mid OH^{-}(aq)\mid Bi_{2}O_{3}(s)\mid Bi(s)$$.

If the reaction quotient at a given time is $$10^{6}$$, then the cell $$EMF (E_{cell})$$ is _____ $$\times 10^{-1} V$$ (Nearest integer).

Given the standard half-cell reduction potential as

$$E_{Bi_{2}O_{3}/Hi,OH^{-}}^{o}=-0.44V \text{ and }E_{Sn(OH)_6^{2-}/HSnO_2^{-}, OH^{-}}^{o}=-0.90V$$

Electricity is passed through an acidic solution of $$Cu^{2+}$$ till all the Cu2+ was exhausted, leading to the deposition of 300 mg of Cu metal. However, a current of 600 mA was continued to pass through the same solution for another 28 minutes by keeping the total volume of the solution fixed at 200 mL. The total volume of oxygen evolved at STP during the entire process is __ mL. (Nearest integer)
[Given:
$$Cu^{2+}(aq)+2e^{-}\rightarrow Cu(s) E_{red}^{\circ}=+0.34V$$
$$O_{2}(g)+4H^{+}+4e^{-}\rightarrow 2H_{2}O E_{red}^{\circ}=+1.23V$$
Molar mass of Cu= 63.54 g $$mol^{-1}$$
Molar mass of $$O_{2}$$ = 32 g $$mol^{-1}$$
Farnday Constant = 96500 C $$mol^{-1}$$
Molar volume at STP = 22.4 L]

Consider the following redox reaction taking place in acidic medium
$$BH_{4}^{-}(aq)+ClO_{3}^{-}(aq)\rightarrow H_{2}BO_{3}^{-}(aq)+Cl^{-}(aq)$$
If the Nerst equation for the above balanced reaction is $$E_{cell}=E_{cell}^{\circ}-\frac{RT}{nF}ln Q$$, then the value of n is______.(Nearest integer)

Consider the above electrochemical cell where a metal electrode (M) is undergoing redox reaction by forming $$M^{+}(M\rightarrow M^{+}+e^{-})$$. The cation $$M^{+}$$ is present in two different concentrations $$c_{1}$$ and $$c_{2}$$ as shown above. which of the following statement is correct for generating a positive cell potential?

The plot of $$\log_{10}^{K} VS \frac{1}{T}$$ gives a straight Line. The intercept and slope respectively are
(where K is equilibrium constant).

A volume of x mL of 5 M $$NaHCO_{3}$$ solution was mixed with 10 mL of 2 M $$H_{2}CO_{3}$$ solution to make an electrolytic buffer. If the same buffer was used in the following electrochemical cell to record a cell potential of 235.3 mV, then the value of x=_______ mL (nearest integer).
$$Sn(s)|Sn(OH)_{6}^{2-}(0.5 M)|HSnO_{2}^{-}(0.05 M)|OH^{-}|Bi_{2}O_{3}(s)|Bi(s)$$
Consider upto one place of decimal for intermediate calculations

For strong electrolyte $$\lambda_m$$ increases slowly with dilution and can be represented by the equation
$$\Lambda_m = \Lambda_m^\circ - A c^{1/2}$$
Molar conductivity values of the solutions of strong electrolyte AB at 18°C are given below:

The value of constant A based on the above data [in S $$cm^{2}mol^{-1}/(mol/L)^{1/2}$$]unit is_______.

Given below are two statements : Statement (I) : Corrosion is an electrochemical phenomenon in which pure metal acts as an anode and impure metal as a cathode. Statement (II) : The rate of corrosion is more in alkaline medium than in acidic medium. In the light of the above statements, choose the correct answer from the options given below :

Which of the following electrolyte can be used to obtain $$H_2 S_2 O_8 $$ by the process of electrolysis?

A solution of aluminium chloride is electrolysed for 30 minutes using a current of 2 A . The amount of the aluminium deposited at the cathode is [Given : molar mass of aluminium and chlorine are 27g $$mol^{-1} $$ and 35.5 g $$mol^{-1}$$ respectively. Faraday constant $$=96500C mol^{-1}$$ ]

Standard electrode potentials for a few half cells are mentioned below :
$$E_{Cu^{2+}/Cu}^{\circ}=0.34 V,E_{Zn^{2+}/Zn}^{\circ}=-0.76 V\\E_{Ag^{+}/Ag}^{\circ}=0.80 V,E_{Mg^{2+}/Mg}^{\circ}=-2.37 V$$ Which one of the following cells gives the most negative value of $$\Delta G^{\circ}$$ ?

For the given cell $$Fe^{2+}_{(aq)} + Ag^+_{(aq)} \rightarrow Fe^{3+}_{(aq)} + Ag_{(s)},$$ the standard cell potential of the above reaction is Given: $$\begin{aligned}Ag^+ + e^- &\rightarrow Ag \qquad E^\circ = x\,V \\Fe^{2+} + 2e^- &\rightarrow Fe \qquad E^\circ = y\,V \\Fe^{3+} + 3e^- &\rightarrow Fe \qquad E^\circ = z\,V \end{aligned}$$

Based on the data given below: $$\begin{aligned}E^\circ_{\text{Cr}_2\text{O}_7^{2-}/\text{Cr}^{3+}} &= 1.33 \text{V} &E;^\circ_{\text{Cl}_2/\text{Cl}^-} &= 1.36\ \text{V} \\E^\circ_{\text{MnO}_4^-/\text{Mn}^{2+}} &= 1.51 \text{V} &E;^\circ_{\text{Cr}^{3+}/\text{Cr}} &= -0.74\ \text{V}\end{aligned}$$ the strongest reducing agent is:

Given below is the plot of the molar conductivity vs $$\sqrt{concentration}$$ for KCl in aqueous solution.

If, for the higher concentration of KCl solution, the resistance of the conductivity cell is 100Ω, then the resistance of the same cell with the dilute solution is $$'n'$$ Ω The value of $$x$$ is __________ (Nearest integer)

The molar conductivity of a weak electrolyte when plotted against the square root of its concentration, which of the following is expected to be observed ?

The standard reduction potential values of some of the p-block ions are given below. Predict the one with the strongest oxidising capacity.

For a $$Mg|Mg^{2+}(aq)||Ag^{+}(aq)|Ag$$ the correct Nernst Equation is :

$$FeO_{4}^{2-}\xrightarrow{+2.0_{V}} Fe^{3+}\xrightarrow{0.8_{V}} Fe^{2+}\xrightarrow{-0.5_{V}}Fe^{0}$$ In the above diagram, the standard electrode potentials are given in volts (over the arrow). The value of $$E_{FeO_{4}^{2-}/Fe^{2+}}^{0}$$ is

$$O_{2}$$ gas will be evolved as a product of electrolysis of : (A) an aqueous solution of $$AgNO_{3}$$ using silver electrodes. (B) an aqueous solution of $$AgNO_{3}$$ using platinum electrodes. (C) a dilute solution of $$H_{2}SO_{4}$$ using platinum electrodes. (D) a high concentration solution of $$H_{2}SO_{4}$$ using platinum electrodes. Choose the correct answer from the options given below :

Match List - I with List - II :

Choose the correct answer from the options given below :

What pressure (bar) of H₂ would be required to make emf of hydrogen electrode zero in pure water at 25°C?

One of the commonly used electrode is calomel electrode. Under which of the following categories, calomel electrode comes?

Electrolysis of 600 mL aqueous solution of NaCl for 5 min changes the pH of the solution to 12 . The current in Amperes used for the given electrolysis is ____. (Nearest integer).

The potential for the given half cell at 298K is $$- x \times 10^{-2}$$ V.
$$2H^+_{(aq)} + 2e^- \rightarrow H_2(g)$$, $$[H^+] = 1$$ M, $$P_{H_2} = 2$$ atm.
(Given $$2.303\ RT/F = 0.06$$ V, $$\log 2 = 0.3$$). The value of $$x$$ is:

The amount of electricity in Coulomb required for the oxidation of 1 mol of $$H_2O$$ to $$O_2$$ is ______ $$\times 10^5$$ C.

Consider the following redox reaction: $$MnO_4^- + H^+ + H_2C_2O_4 \rightleftharpoons Mn^{2+} + H_2O + CO_2$$
The standard reduction potentials are given as below:
$$E^0_{MnO_4^-/Mn^{2+}} = +1.51$$ V; $$E^0_{CO_2/H_2C_2O_4} = -0.49$$ V
If the equilibrium constant of the above reaction is given as $$K_{eq} = 10^x$$, then the value of $$x$$ = ______ (nearest integer)

The mass of silver (Molar mass of Ag : $$108 \text{ g mol}^{-1}$$) displaced by a quantity of electricity which displaces $$5600$$ mL of $$O_2$$ at S.T.P. will be ______ g.

Which of the following statements is not correct about rusting of iron?

The hydrogen electrode is dipped in a solution of pH = 3 at 25°C. The potential of the electrode will be $$-$$ _____ $$\times 10^{-2}$$ V.
$$\frac{2.303RT}{F} = 0.059$$ V. Round off the answer to the nearest integer.

The mass of zinc produced by the electrolysis of zinc sulphate solution with a steady current of $$0.015$$ A for $$15$$ minutes is _______ $$\times 10^{-4}$$ g. (Atomic mass of zinc $$= 65.4$$ amu)

A constant current was passed through a solution of $$AuCl_4^-$$ ion between gold electrodes. After a period of $$10.0$$ minutes, the increase in mass of cathode was $$1.314$$ g. The total charge passed through the solution is ______ $$\times 10^{-2}$$ F. (Given atomic mass of Au = 197)

The metals that are employed in the battery industries are A. Fe, B. Mn, C. Ni, D. Cr, E. Cd. Choose the correct answer from the options given below:

Identify the factor from the following that does not affect electrolytic conductance of a solution.

One Faraday of electricity liberates $$x \times 10^{-1}$$ gram atom of copper from copper sulphate, $$x$$ is ______.

The values of conductivity of some materials at 298.15 K in S m$$^{-1}$$ are $$2.1 \times 10^3$$, $$1.0 \times 10^{-16}$$, $$1.2 \times 10$$, $$3.91$$, $$1.5 \times 10^{-2}$$, $$1 \times 10^{-7}$$, $$1.0 \times 10^3$$. The number of conductors among the materials is

For a strong electrolyte, a plot of molar conductivity against (concentration)$$^{1/2}$$ is a straight line, with a negative slope, the correct unit for the slope is:

Fuel cell, using hydrogen and oxygen as fuels: A. has been used in spaceship, B. has an efficiency of 40% to produce electricity, C. uses aluminum as catalysts, D. is eco-friendly, E. is actually a type of Galvanic cell only. Choose the correct answer from the options given below:

The quantity of silver deposited when one coulomb charge is passed through $$AgNO_3$$ solution :

For the electrochemical cell, if $$E^0_{(M^{2+}/M)} = 0.46$$ V and $$E^0_{(X/X^{2-})} = 0.34$$ V. Which of the following is correct?

The reaction at cathode in the cells commonly used in clocks involves.

Molar ionic conductivities of divalent cation and anion are $$57 \text{ S cm}^2 \text{ mol}^{-1}$$ and $$73 \text{ S cm}^2 \text{ mol}^{-1}$$ respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be :

A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will -

How can an electrochemical cell be converted into an electrolytic cell?

The emf of cell

It could be increased by :

The reaction; $$\frac{1}{2}H_{2(g)} + AgCl_{(s)} \rightarrow H^+_{(aq)} + Cl^-_{(aq)} + Ag_{(s)}$$ occurs in which of the following galvanic cell :