Electro chemistry practice · Easy

The correct order of electro chemical equivalent (e) of Sodium, Magnesium and Aluminium is

Hydrogen-oxygen fuel cells are used in spacecraft to supply :

The correct value of e.m.f. of cell is given by :

i) ${E_{cell}} = {E_{OP}}{\kern 1pt} anode - {E_{RP}}{\kern 1pt} cathode$

ii) ${E_{cell}} = {E_{OP}}{\kern 1pt} anode + {E_{RP}}{\kern 1pt} cathode$

iii) ${E_{cell}} = {E_{RP}}{\kern 1pt} anode + {E_{RP}}{\kern 1pt} cathode$

iv) ${E_{cell}} = {E_{OP}}{\kern 1pt} anode - {E_{OP}}{\kern 1pt} cathode$

$100 \mathrm{~g} \mathrm{~Al}$ is to be deposited on the cathode of the electrolytic cell containing $\mathrm{Al}_2 \mathrm{O}_3$ in the solvent $\mathrm{Na}_3 \mathrm{AlF}_6$ by a current of $125 \mathrm{~A}$. If at the cathode, reaction is

$\mathrm{Al}^{3+}+3 e^{-} \longrightarrow \mathrm{Al}$

then time required for the passage of current is $(\mathrm{Al}=27)$

Pure water does not conduct electricity because it is

In electrolysis, oxidation takes place at:

The amount of electricity that can deposit 108 g of
silver from silver nitrate solution is

The charge required to liberate one gram equivalent of an element is

$E^\circ$ values of some redox couples are given below on the basis of these values. Choose the correct option
$E^\circ$ values:
$\begin{array}{l} B{r_2}\mathrm{/}B{r^ - } = + 1.90\\ A{g^ + }\mathrm{/}Ag(s) = + 0.80\\ C{u^{2 + }}\mathrm{/}Cu(s) = + 0.34\\ {I_2}(s)\mathrm{/}{I^ - } = + 0.54 \end{array}$

The oxidation potential of Mg and Al are + 2.37 and + 1.66 volt respectively. The Mg in chemical reactions :

A steady current of 30.0 A for 70.2 min corresponds to a
passage of

Assertion (A): ${KMnO}_4$ act as only oxidizing agent.

Reason (R): In ${KMnO}_4, {Mn}$ is in its highest oxidation state +7.

The position of some metals in the electrochemical series in decreasing electropositive character is given as $\mathrm{Mg} > Al > Zn > Cu > Ag$. What will happen, if a copper spoon is used to stir a solution of aluminium nitrate?

The laws of electrolysis were proposed by

Rust is

What will be pH of aqueous solution of electrolyte in electrolytic cell during electrolysis of $\mathrm{CuS}{\mathrm{O}_4}\left( {aq} \right)$ between graphite electrodes?

Rusting of iron is catalysed by which of the following?

In an electrolytic cell, the anode and cathode are respectively represented as :

Which of the following statements is/are incorrect?

Consider the following cell representation:
$\mathrm{Pt}(\mathrm{s})\left|\mathrm{Br}_2({l})\right| \mathrm{Br}^{\ominus}(0.010)|| \mathrm{H}^{\oplus}(0.030 \mathrm{~M})\left|\mathrm{H}_2(\mathrm{g})(1 \mathrm{~bar})\right| \mathrm{Pt}(\mathrm{s})$
The EMF of the above cell at $298 \mathrm{~K}$ is $-\mathrm{xV}$. Find $3 \mathrm{x}$ (nearest integer)

$\begin{aligned} & \text {[Given } \mathrm{E}^{\circ}_{\frac{1}{2}\mathrm{Br}_2 \mid \mathrm{Br}^{-}} \text{ (Reduction potential of } \mathrm{Br}_2)=+1.08 \mathrm{~V} \text {]} \end{aligned}$

Electrode potential of hydrogen electrode is …….. Volt.

A standard hydrogen electrode has Zero electrode potential because

The formula $\mathrm{\alpha } = \frac{{{\mathrm{\Lambda }_\mathrm{v}}}}{{{\mathrm{\Lambda }_\infty }}}$ is valid for :

${E^ \circ }$ of an electrode is :

The fraction of the total current carried by an ion is known as:

Galvanic cell is A device in which

Out of $Cu, Ag, Fe$ and $Zn$, the metal which can displace all others form their salt solutions is:

Statement (S): Conductivity of weak electrolytic solution decreases with dilution whereas equivalent conductivity, molar conductivity increases with dilution.
Explanation (E): On dilution, the ionic mobility and number of ions present in solution increases but number of ions per mL decreases.

If mercury is used as cathode in the electrolysis of aqueous $NaCl$ solution, the ions discharged at cathode is

The molar conductivity at infinite dilution of $\mathrm{AgN}{\mathrm{O}_3},\mathrm{NaCl}$ and $\mathrm{NaN}{\mathrm{O}_3}$ are 116.5, 110.3 and 105.2 ${\rm{mho{\kern 1pt} {\kern 1pt} c}}{\mathrm{m}^2}{\kern 1pt} {\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$ respectively. The molar conductivity of AgCl is :