Electrochemistry - Physical Chemistry - Chemistry Previous Year Questions

By passing electric current, $\mathrm{NaClO}_3$ is converted in to $\mathrm{NaClO}_4$ according to the following equation

$$\mathrm{NaClO}_3+\mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{NaClO}_4+\mathrm{H}_2$$

How many moles of $\mathrm{NaClO}_4$ will be formed when three Faradays of charges is passed through $\mathrm{NaClO}_3$ ?

In the electrolysis of aqueous sodium chloride solution, which of the half cell reaction will occur at anode?

The standard reduction potential at 298 K for the following half cell reaction

$$\begin{aligned} & 2 \mathrm{n}^{2+}(a q)+2 e^{-} \rightarrow \mathrm{Zn}(s) ; E^0=-0.762 \mathrm{~V} \\ & \mathrm{Cr}^{3+}(a q)+3 e^{-} \rightarrow \mathrm{Cr}(s) ; E^0=0.740 \mathrm{~V} \\ & 2 \mathrm{H}^{+}(a q)+2 e^{-} \rightarrow \mathrm{Hz}(g) ; E^0=0.0 \mathrm{~V} \\ & \mathrm{~F}_2(g)+2 e^{-} \rightarrow 2 \mathrm{~F}^{-}(a q) ; E^0=2.87 \mathrm{~V} \end{aligned}$$

Which of the following is strongest reducing agent?

An aqueous solution of \(\mathrm{CuSO}_4\) is subjected to electrolysis using inert electrodes. The \(\mathrm{pH}\) of the solution will

Give \(E_{\mathrm{Mn}^{+7} \mid \mathrm{Mn}^{+2}}^0=1.5 \mathrm{~V}\) and \(E_{\mathrm{Mn}^{+4}\mid \mathrm{Mn}^{+2}}^0=1.2 \mathrm{~V}\), then \(E_{\mathrm{Mn}^{+7} \mid \mathrm{Mn}^{+4}}^0\) is

One litre solution of \(\mathrm{MgCl}_2\) is electrolysed completely by passing a current of \(1 \mathrm{~A}\) for \(16 \mathrm{~min} 5 \mathrm{~sec}\). The original concentration of \(\mathrm{MgCl}_2\) solution was (Atomic mass of \(\mathrm{Mg}=24\) )

Addition of excess of \(\mathrm{AgNO}_3\) to an aqueous solution of 1 mole of \(\mathrm{PdCl}_2 \cdot 4 \mathrm{NH}_3\) gives 2 moles of \(\mathrm{AgCl}\). The conductivity of this solution corresponds to

If an aqueous solution of \(\mathrm{NaF}\) is electrolysed between inert electrodes, the product obtained at anode is

The pair of electrolytes that posses same value for the constant \((A)\) in the Debye-Huckel-Onsager equation, \(\Lambda_m=\Lambda_m^{\circ}-A \sqrt{C}\) is

Given \(E_{F{e^{3 + }}/F{e^{2 + }}}^o = + 0.76\,V\) and \(E_{\mathrm{I}_2 / \mathrm{I}^{-}}^0=+0.55 \mathrm{~V}\). The equilibrium constant for the reaction taking place in galvanic cell consisting of above two electrodes is \(\left[\frac{2303 R T}{F}=0.06\right]\)

$$\mathrm{H}_2(g)+2 \mathrm{AgCl}(s) \rightleftharpoons 2 \mathrm{Ag}(s)+2 \mathrm{HCl}(a q)$$

\(E_{\text {cell }}^{\circ}\) at \(25^{\circ} \mathrm{C}\) for the cell is \(0.22 \mathrm{~V}\). The equilibrium constant at \(25^{\circ} \mathrm{C}\) is

The resistance of \(0.01 \mathrm{~m} \mathrm{~KCl}\) solution at \(298 \mathrm{~K}\) is \(1500 \Omega\). If the conductivity of \(0.01 \mathrm{~m} \mathrm{~KCl}\) solution at \(298 \mathrm{~K}\) is \(0.1466 \times 10^{-3} \mathrm{~S} \mathrm{~cm}^{-1}\). The cell constant of the conductivity cell in \(\mathrm{cm}^{-1}\) is

Consider the following electrodes

$$\begin{aligned} & P=\mathrm{Zn}^{2+}(0.0001 \mathrm{M}) / \mathrm{Zn}, Q=\mathrm{Zn}^{2+}(0.1 \mathrm{M}) / \mathrm{Zn} \\ & R=\mathrm{Zn}^{2+}(0.01 \mathrm{M}) / \mathrm{Zn}, S=\mathrm{Zn}^{2+}(0.001 \mathrm{M}) / \mathrm{Zn} \end{aligned}$$

\(E^{\circ}(\mathrm{Zn} / \mathrm{Zn}^{2+})=-0.76 \mathrm{~V}\) electrode potentials of the above electrodes in volts are in the order

In fuel cells _______ are used as catalysts.

For spontaneity of a cell, which is correct?

The molar conductivity is maximum for the solution of concentration