Electro chemistry practice · Mixed difficulty

A gas $X$ at 1 atm is bubbled through a solution containing a mixture of 1 M ${y^ - }$ and 1 M ${z^ - }$ at ${25^ \circ }C$. If the order of reduction potential is $z > y > x$ then

Deduce from the following ${E^ \circ }$ values of half cells, what combination of two half cells would result in a cell with the largest potential?

i)${A^{3 - }} \to {A^{2 - }} + e;$ ${E^ \circ } = 1.5\mathrm{V}$

ii) ${B^{2 + }} + e \to {B^ + }$; ${E^ \circ } = - 2.1\mathrm{V}$

iii) ${C^{2 + }} + e \to {C^ + }$; ${E^ \circ } = 0.5\mathrm{V}$

iv) $D \to {D^{2 + }} + 2e$; ${E^ \circ } = - 1.5\mathrm{V}$

${E^\mathrm{o}}\mathrm{ \,for }\,{F_2} + 2{e^ - } \to 2{F^ - }\mathrm{ \,is }\,\,2.8\,V$ , ${E^\mathrm{o}}\mathrm{ \,\,for}\,\,\,\mathrm{ }\frac{1}{2}{F_2} + {e^ - } \to {F^ - }\mathrm{ is:}$

Which of the following is an additive property?

Assertion (A): DC can not be used during measurement of resistance of an ionic solution.

Reason (R): DC changes the composition of solution and solution cannot be connected to the bridge like metallic wire.

${E^0}$ for the half cell $Z{n^{2 + }}/Zn$ is $- 0.76$, e.m.f of the cell $Zn/Z{n^{2 + }}\left( {1M} \right)//2{H^ + }\left( {2M} \right)/{H_2}\left( {1\,{\text{atm}}} \right)$ is

$\mathrm{MnO}_4^ - + 8{\mathrm{H}^ + } + 5{e^ - } \to \mathrm{M}{\mathrm{n}^{2 + }} + 4{\mathrm{H}_2}\mathrm{O};{E^ \circ } = 1.51\mathrm{V}$

$\mathrm{Mn}{\mathrm{O}_4} + 4{\mathrm{H}^ + } + 2{e^ - } \to \mathrm{M}{\mathrm{n}^{2 + }} + 2{\mathrm{H}_2}\mathrm{O};{E^ \circ } = 1.23\mathrm{V}$

$E_{\mathrm{MnO}_4^ - |\mathrm{Mn}{\mathrm{O}_2}}^ \circ$ is

The potential of the following cell is 0.34 V at ${25^ \circ }C$. Calculate the standard reduction potential of the copper half-cell.

$\mathrm{Pt}\left| {{\mathrm{H}_2}\left( {1{\kern 1pt} {\kern 1pt} \mathrm{atm}} \right)} \right|{\mathrm{H}^ + }\left( {1\mathrm{M}} \right)|\left| {\mathrm{C}{\mathrm{u}^{2 + }}\left( {1\mathrm{M}} \right)} \right|\mathrm{Cu}$

The standard H electrode is written as :

Give the products available on the cathode and the anode respectively during the electrolysis of an aqueous solution of $\mathrm{MgS}{\mathrm{O}_4}$ between inert electrodes.

A volume of $100 \mathrm{~ml}$ of a buffer of $1 \mathrm{~M}-\mathrm{NH}_3$ and $1 \mathrm{~M}-\mathrm{NH}_4^{+}$ is placed in two half-cells connected by a salt bridge. A current of $1.5 \mathrm{~A}$ is passed through the cell for $20 \mathrm{~min}.$ If electrolysis of water takes place only and the electrode reactions are:

Right: $2 \mathrm{H}_2 \mathrm{O}+\mathrm{O}_2+4 \mathrm{e} \rightarrow 4 \mathrm{OH}^{-}$

and Left: $2 \mathrm{H}_2 \mathrm{O} \rightarrow 4 \mathrm{H}^{+}+\mathrm{O}_2+4 \mathrm{e}$, then, the $\mathrm{pH}$ of

Which of the following statements is correct? Galvanic cell converts:

In the plot of $\wedge$ and $\sqrt C$ , the slop is

$\mathrm{C}{\mathrm{u}^ + }\left( {aq} \right)$ is unstable in solution and undergoes simultaneous oxidation and reduction, according to the reaction
$2\mathrm{C}{\mathrm{u}^ + }\left( {aq} \right)\leftrightharpoons\mathrm{C}{\mathrm{u}^{2 + }}\left( {aq} \right) + \mathrm{Cu}\left( s \right)$
choose correct ${E^ \circ }$ for the above reaction if
$E_{\mathrm{C}{\mathrm{u}^{2 + }}/\mathrm{Cu}}^ \circ = 0.34\mathrm{V},E_{\mathrm{C}{\mathrm{u}^{2 + }}/\mathrm{C}{\mathrm{u}^ + }}^ \circ = 0.15\mathrm{V}$

Electrolysis of aq. Solution of $\mathrm{LiCl}$ shows :

The amount of an ion discharged during electrolysis is not dependent of :

What is the quantity of electricity (in Coulombs) required to deposit all the silver from 250mL of 1 $\mathrm{MAgN}{\mathrm{O}_3}$ solution?

The $E_{{M^{3 + }}/{M^{2 + }}}^ \circ$ values for Cr, Mn, Fe and Co are -0.41 V, +1.57 V, +0.77 V and +1.97 V respectively. For which one of these metals the change in oxidation state from +2 to +3 is easiest?

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]

A cell in which electric current is produced by net oxidation and reduction process is called :

A substance that will reduce $\mathrm{A}{\mathrm{g}^ + }$ to Ag but will not reduce $\mathrm{N}{\mathrm{i}^{2 + }}$ to Ni is :

The equation that is incorrect is

Which does not get oxidised by bromine water?

Which of the following expression is correct?

Consider the reaction, ${M^{n + }}\left( {aq} \right) + ne \to {M^ \circ }\left( s \right).$ The standard reduction potential values of the metals ${M_1},{M_2}$ and ${M_3}$ are $- 0.34\mathrm{V}, - 3.05\mathrm{V}$ and $- 1.66\mathrm{V}$ respectively. The order of their reducing power will be :

How long (in hours) must a current of 5.0 A be maintained to electroplate 60 g of calcium from molten $\mathrm{CaC}{\mathrm{l}_2}$ ?

${E^ \circ }$ for $\mathrm{F}{\mathrm{e}^{2 + }} + 2{\mathrm{e}^ - } \to \mathrm{Fe}$ is -0.44 V and ${E^ \circ }$ for

$\mathrm{Z}{\mathrm{n}^{2 + }} + 2{\mathrm{e}^ - } \to \mathrm{Zn}$ is -0.76 V thus

The reactions taking place at anode and cathode are

${E^\mathrm{o}}$ for the half cell, $Z{n^{2 + }}/Zn$ is $- 0.76$, then emf of the cell $Zn/Z{n^{2 + }}\left( {1M} \right)//2{H^ + }\left( {1M} \right)/{H_2}\left( {1\,\,\mathrm{atm}} \right)$ is

Given below are two statements.
Statement I The limiting molar conductivity of $KCl$ (strong electrolyte) is higher compared to that of $C{H_3}COOH$ (Weak electrolyte).
Statement II Molar conductivity decreases with decrease in concentration of electrolyte.
In the light of the above statements, choose the most appropriate answer from the options given below.