Electro chemistry practice · Mixed difficulty

The equivalent conductivity of $0.05\,\,N$ solution of a monobasic acid ${\text{15}}{\text{.8}}\,\,{\text{mho}}\,\,\,{\text{c}}{{\text{m}}^{\text{2}}}{\text{e}}{{\text{q}}^{ - 1}}.$ If equivalent conductivity of the acid at infinite dilution is $350\,\,{\text{mho}}\,\,\,{\text{c}}{{\text{m}}^{\text{2}}}{\text{e}}{{\text{q}}^{ - 1}}$ at the same temperature. What is the degree of dissociation and dissociation constant of acid?

Assertion (A): Molar conductivity increases with decrease in concentration for weak electrolytes.

Reason (R): The degree of dissociation increases on dilution for a weak electrolyte.

The electrolysis of a solution resulted in the formation of ${\mathrm{H}_2}$ at the cathode and $\mathrm{C}{\mathrm{l}_2}$ at the anode. The liquid is:

Which of the following statements is not correct about an inert electrode in a cell?

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

At ${18^ \circ }\mathrm{C}$ the conductance of ${\mathrm{H}^ + }$ and $\mathrm{C}{\mathrm{H}_3}\mathrm{CO}{\mathrm{O}^ - }$ at infinite dilution are 315 and 35 ${\rm{mho {\kern 1pt} {\kern 1pt} c}}{\mathrm{m}^2}{\kern 1pt} {\kern 1pt} \mathrm{e}{\mathrm{q}^{ - 1}}$ respectively. The equivalent conductivity of $\mathrm{C}{\mathrm{H}_3}\mathrm{COOH}$ at infinite dilution is ……${\rm{mho {\kern 1pt} {\kern 1pt} c}}{\mathrm{m}^2}{\kern 1pt} {\kern 1pt} \mathrm{eq}{.^{ - 1}}$

${E}_{{A\ell}^{+3} / {A} \ell}=-1.66 {~V} \& {~K}_{{sp}}$ of ${A} \ell({OH})_3=1.0 \times 10^{-33}$ Reduction potential of the above couple at ${pH}=14$ is

The acid used in lead storage battery is:

The electrochemical cell stops working after sometimes because

The composition of rust is

According to Faraday’s first law of electrolysis mass of substances liberated is equal to

Iron powder is added to $1.0 \mathrm{~M}$ solution of ${CdCl}_2$ at $298 \mathrm{~K}$. The reaction occurring is ${Cd}^{2+}(a q)+{Fe}(s) \rightarrow {Cd}(s)+{Fe}^{2+}(a q)$. If the standard potential of a cell producing this reaction is $0.037 \mathrm{~V}$, the concentrations of ${Cd}^{2+}$ and ${Fe}^{2+}$ ions in the above reaction at equilibrium respectively will be (Hint:- $\left.10^{1.3}=20\right)$

Aqueous solution of which of the following compounds is the best conductor of electric current?

Hydrogen peroxide is obtained by electrolysis of

The emf of the cell

$\mathrm{Ni}\left| {\mathrm{N}{\mathrm{i}^{2 + }}\left( {1.0\mathrm{M}} \right)} \right|\left| {\mathrm{A}{\mathrm{u}^{3 + }}\left( {1.0\mathrm{M}} \right)} \right|\mathrm{Au}$

is [${\mathrm{E}^ \circ }\left( {\mathrm{N}{\mathrm{i}^{2 + }}/\mathrm{Ni}} \right) =$ -0.25 V and

${E^ \circ }\left( {\mathrm{A}{\mathrm{u}^{3 + }}/\mathrm{Au}} \right) =$ +1.5 V]

Cell constant of a conductivity cell is usually derived by using a solution of :

Copper can be deposited from acidified copper sulphate and alkaline cuprous cyanide. If the same current is passed for a definite time:

An ion is reduced to the element when it absorbs $6 \times {10^{20}}$ electrons. The number of equivalents of the ion is :

${\mathrm{H}_2}$ cannot be displaced by

One Faraday of electricity is passed through molten ${Al}_2 {O}_3$, aqueous solution of ${CuSO}_4$ and molten ${NaCl}$ taken in three different electrolytic cells connected in series. The mole ratio of ${Al}, {Cu}$ and ${Na}$ deposited at the respective cathode is

Molar conductivities (${\mathop \mathrm{\Lambda }\limits^ \circ _m}$) at infinite dilution of $\mathrm{NaCl},\mathrm{HCl}$ and $\mathrm{C}{\mathrm{H}_3}\mathrm{COONa}$ are 126.4, 425.9 and 91.0 ${\rm{S {\kern 1pt} {\kern 1pt}c}}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$ respectively.${\mathop \mathrm{\Lambda }\limits^ \circ _m}$ for $\mathrm{C}{\mathrm{H}_3}\mathrm{COOH}$ will be :

The increase in equivalent conductivity of a weak electrolyte solution with dilution is attributed to :

Equivalence conductance at infinite dilution of ${NH}_4 {Cl}, {NaOH}$ and ${NaCl}$ are $129.8, 217.4$ and $108.9 \, \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1},$ respectively. If the equivalent conductance of $0.01 \mathrm{~N}$ solution of ${NH}_4 {OH}$ is $9.532 \, \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1},$ then the degree of dissociation of ${NH}_4 {OH}$ at this temperature is

Calculate the volume of hydrogen at NTP obtained by passing a current of 0.4 ampere through acidified water for 30 minute :

Given the following molar conductivities at $25^{\circ} \mathrm{C}, \mathrm{HCl}, 426 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1} ; \mathrm{NaCl}, 126 \Omega^{-1}$ $\mathrm{cm}^2 \mathrm{~mol}^{-1} ; \mathrm{NaC}$ (sodium crotonate), $83 \Omega^{-1}$ $\mathrm{cm}^2 \mathrm{~mol}^{-1}$. What is the dissociation constant of crotonic acid, if the conductivity of a $0.001 \mathrm{M}$ crotonic acid solution is $3.83 \times 10^{-5} \Omega^{-1} \mathrm{~cm}^{-1}$ ?

The reduction potential of a hydrogen electrode having $\mathrm{pH}$ value '${x}$' and ${y}$ atm pressure of ${H}_2$-gas at $25^{\circ} \mathrm{C}$ is correctly given as

Statement I: When iron rod is immersed in $\mathrm{NaCl}$ solution such that half of its length is corroded and other half part when exposed to air is not corroded.

Statement II: Metal portion with less access to $\mathrm{O}_2$ corrodes.

The electroplating with chromium is undertaken because :

Standard electrode potentials of two half cells are given as
$Z{n^{2 + }}/Zn = - 0.76\,\,V$

$A{g^ + }/Ag = 0.80\,V$
The EMF of the cell $Zn\left| {Z{n^{2 + }}\left( {1M} \right)} \right|\left| {A{g^ + }\left( {1M} \right)} \right|Ag$ will be:

A current of 9.65 flowing for 10 minute deposits 3.0 g of a metal. The equivalent weight of the metal is