Electro chemistry practice · Medium

A hydrogen gas electrode is made by dipping platinum wire in a solution of HCl of pH = 4 and passing hydrogen gas around the platinum wire at one atm pressure and at 298 K. The reduction potential of the hydrogen electrode would be

A cell with two electrodes, one of grey tin and the other white tin, both dipping in solution of ${\left( {\mathrm{N}{\mathrm{H}_4}} \right)_2}\mathrm{SnC}{\mathrm{l}_6}$ showed zero e.m.f. at ${18^ \circ }C$. What conclusion may be drawn from this?

For a given cell reaction; $Cr + 3{H_2}O + OC{l^ - } \to C{r^{+3}}+3C{l^ - } + 6O{H^ - },$ the species undergoing reduction is :

A galvanic cell is composed of two hydrogen electrodes, one of which is a standard one. In which of the following solutions should the other electrode be immersed to get maximum e. m. f.?

Which equation gives relation between concentration of ions is solution, electrode potential ($E$) and standard electrode potential $\left(E^0\right)$

A silver cup is plated with silver by passing 965 C of electricity. The amount of Ag deposited is

When during electrolysis of a solution of a $\mathrm{AgN}{\mathrm{O}_3},9650\mathrm{C}$ of charge pass through the electroplating bath, the mass of silver deposited on the cathode will be

The standard electrode potential for the half – cell reactions are
$\mathrm{Z}{\mathrm{n}^{2 + }} + 2{e^ - } \to \mathrm{Zn};{E^ \circ }$ = -0.76 V
$\mathrm{F}{\mathrm{e}^{2 + }} + 2{e^ - } \to \mathrm{Fe};{E^ \circ }$ = -0.44 V
The emf of the cell reaction,
$\mathrm{F}{\mathrm{e}^{2 + }} + \mathrm{Zn} \to \mathrm{Z}{\mathrm{n}^{2 + }} + \mathrm{Fe}$ is

On passing electricity through dil. ${H_2}S{O_4}$ solution, the amount of substance liberated at the cathode and anode are in the ratio

The emf of the cell, $\left( {{E_{\mathrm{Z}{\mathrm{n}^{2 + }}/\mathrm{Zn}}} = - 0.76V} \right)$

$\mathrm{Zn}/\mathrm{Z}{\mathrm{n}^{2 + }}\left( {1\mathrm{M}} \right)|\left| {\mathrm{C}{\mathrm{u}^{2 + }}\left( {1\mathrm{M}} \right)} \right|\mathrm{Cu}$

$\left( {{E_{\mathrm{C}{\mathrm{u}^{2 + }}/\mathrm{Cu}}} = + 0.34V} \right)$ will be

Statement (S): A graph plotted between ${\Lambda _v}\,vs.\,{c^{1/2}}$ gives a straight line with slope equal to $- A$ and intercept equal to ${\Lambda _\infty }$
Explanation (E): The value of $A$ for a given solvent and temperature depends upon the nature of electrolyte, i.e., charge on cation or anion furnished by electrolyte on dissolution.

In the electrochemical reaction,

$2\mathrm{F}{\mathrm{e}^{3 + }} + \mathrm{Zn} \to \mathrm{Z}{\mathrm{n}^{2 + }} + 2\mathrm{F}{\mathrm{e}^{2 + }}$

increasing the concentration of $\mathrm{F}{\mathrm{e}^{2 + }}$

The E0 values at ${25^0}C$ for ${A^ + }/A,\mathrm{ }{B^{2 + }}/B,\mathrm{ }{D^{3 + }}/D$ and ${E^ + }/E$ are -2.15, -1.75, +0. 15 and +0.21 volt respectively. Which of the following is the strongest oxidising agent ?

When Zn piece is kept in $\mathrm{CuS}{\mathrm{O}_4}$ solution, copper gets precipitated because:

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 equilibrium constant for the reaction at 298 K is

Statement I: During electrolysis of aqueous
sodium acetate solution, the molar ratio of gases
formed at cathode and anode is 1:3.

Statement II: Acetate ion discharges at anode and
$\text{H}^+$ ion, at cathode.

On passing 0.5 F electricity through molten sodium chloride, sodium deposited at cathode will be

1.8 g of metal were deposited by a current of 3 amperes for 50 minute. The equivalent wt. of metal is :

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?

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

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

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

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?

Which does not get oxidised by bromine water?

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 :

The reactions taking place at anode and cathode are

A current of strength 2.5 A was passed through $\mathrm{CuS}{\mathrm{O}_4}$ solution for 6 min 26 s. The amount of copper deposited is (At. Wt. of Cu = 63.5, 1F = 96500 C)

A certain metal fails to liberate ${\mathrm{H}_2}$ gas from a moderately conc. HCl solution. However, it displaces $\mathrm{Ag}$ from $\mathrm{AgN}{\mathrm{O}_3}$ solution. Which among the followings may it be?