Electrochemistry

To find the standard potential of $\ce{M^3+/M}$ electrode, the following cell is constituted : $\ce{Pt/M/M^3+}$(0.001 mol L$^{-1}$)/$\ce{Ag+}$(0.01 mol L$^{-1}$)/Ag

The emf of the cell is found to be 0.421 volt at 298 K. The standard potential of half reaction $\ce{M^3+ + 3e- -> M}$ at 298 K will be :

(Given $E^\circ_{\ce{Ag+/Ag}}$ at 298 K = 0.80 Volt)

Which of the following ions does not liberate hydrogen gas on reaction with dilute acids ?

For the following electrochemical cell at 298 K,
$$\mathrm{Pt}(s)\mid\ce{H2}(g,1\text{ bar})\mid\ce{H+}(aq,1\text{ M})\parallel\ce{M^{4+}}(aq),\ce{M^{2+}}(aq)\mid\mathrm{Pt}(s)$$
$E_{cell}=0.092$ V when $\dfrac{[\ce{M^{2+}}(aq)]}{[\ce{M^{4+}}(aq)]}=10^x$.

Given: $E^0_{\ce{M^{4+}}/\ce{M^{2+}}}=0.151$ V; $2.303\dfrac{RT}{F}=0.059$ V

The value of $x$ is

Galvanization is applying a coating of :

What will occur if a block of copper metal is dropped into a beaker containing a solution of 1M $\ce{ZnSO4}$ ?

Oxidation of succinate ion produces ethylene and carbon dioxide gases. On passing 0.2 Faraday electricity through an aqueous solution of potassium succinate, the total volume of gases (at both cathode and anode) at STP (1 atm and 273 K) is :

Identify the correct statement :

All the energy released from the reaction $\mathbf X\to\mathbf Y$, $\Delta_rG^\circ=-193\ \mathrm{kJ\,mol^{-1}}$ is used for oxidizing $\ce{M+}$ as $\ce{M+ -> M^{3+} + 2e-}$, $E^\circ=-0.25$ V.

Under standard conditions, the number of moles of $\ce{M+}$ oxidized when one mole of X is converted to Y is

$[F=96500\ \mathrm{C\,mol^{-1}}]$

Copper is purified by electrolytic refining of blister copper. The correct statement(s) about this process is(are)

The molar conductivity of a solution of a weak acid HX (0.01 M) is 10 times smaller than the molar conductivity of a solution of a weak acid HY (0.10 M). If $\lambda^0_{\ce{X-}}\approx\lambda^0_{\ce{Y-}}$, the difference in their $\mathrm pK_a$ values, $\mathrm pK_a(\ce{HX})-\mathrm pK_a(\ce{HY})$, is (consider degree of ionization of both acids to be $\ll1$)

Two Faraday of electricity is passed through a solution of $\ce{CuSO4}$. The mass of copper deposited at the cathode is : (at. mass of Cu = 63.5 amu)

A variable, opposite external potential ($E_{ext}$) is applied to the cell $\ce{Zn | Zn^2+ (1 M) || Cu^2+ (1 M) | Cu}$, of potential 1.1 V. When $E_{ext}<1.1$ V and $E_{ext}>1.1$ V, respectively electrons flow from :

At 298 K, the standard reduction potentials are 1.51 V for $\ce{MnO4- | Mn^2+}$, 1.36 V for $\ce{Cl2 | Cl-}$, 1.07 V for $\ce{Br2 | Br-}$, and 0.54 V for $\ce{I2 | I-}$. At pH = 3, permanganate is expected to oxidize : $\left(\dfrac{RT}F=0.059\text{ V}\right)$

In a galvanic cell, the salt bridge

Resistance of 0.2 M solution of an electrolyte is 50 Ω. The specific conductance of the solution is 1.4 S m$^{-1}$. The resistance of 0.5 M solution of the same electrolyte is 280 Ω. The molar conductivity of 0.5 M solution of the electrolyte in S m$^2$ mol$^{-1}$ is :

The equivalent conductance of NaCl at concentration C and at infinite dilution are $\lambda_C$ and $\lambda_\infty$, respectively. The correct relationship between $\lambda_C$ and $\lambda_\infty$ is given as :

(where the constant B is positive)

The metal that cannot be obtained by electrolysis of an aqueous solution of its salts is :

Given below are the half - cell reactions :

$\ce{Mn^2+ + 2e- -> Mn}$ ; $E^\circ=-1.18$ V

$2\left(\ce{Mn^3+ + e- -> Mn^2+}\right)$ ; $E^\circ=+1.51$ V

The $E^\circ$ for $\ce{3Mn^2+ -> Mn + 2Mn^3+}$ will be :

The standard electrode potentials $\left(E^\circ_{\ce{M+}/\ce{M}}\right)$ of four metals A, B, C and D are $-1.2$ V, 0.6 V, 0.85 V and $-0.76$ V, respectively. The sequence of deposition of metals on applying potential is :

A current of 10.0 A flows for 2.00 h through an electrolytic cell containing a molten salt of metal X. This results in the decomposition of 0.250 mol of metal X at the cathode. The oxidation state of X in the molten salt is : ($F=96{,}500$ C)