Embibe Experts Solutions for Chapter: Electrochemistry, Exercise 1: Level 1

The $\mathrm{emf}$ of the cell, $\mathrm{Ni}\left|{\mathrm{Ni}}^{2+}\left(1.0 \mathrm{M}\right)\Vert {\mathrm{Ag}}^{+}\left(1.0 \mathrm{M}\right)\right|\mathrm{Ag}$  [$\mathrm{E}°$  for ${\mathrm{Ni}}^{2+}/\mathrm{Ni}=-0.25$ volt, $\mathrm{E}°$ for ${\mathrm{Ag}}^{+}/\mathrm{Ag}=0.80$ volt] is given by

$\mathrm{Zn}\left|{\mathrm{Zn}}^{2+}\left({\mathrm{C}}_1\right)\Vert {\mathrm{Zn}}^{2+}\left({\mathrm{C}}_2\right)\right|\mathrm{Zn}$ for this cell $\mathrm{\Delta G}$ is negative if

The cell $Pt\left({\mathrm{H}}_2\right)\left(1 \mathrm{atm}\right)\left|{\mathrm{H}}^{+}\left(\mathrm{pH}=?\right)\Vert {\mathrm{I}}^{-}\left(\mathrm{a}=1\right)\right|\mathrm{AgI}\left(\mathrm{s}\right)$, $\mathrm{Ag}$ has $\mathrm{emf}$, ${\mathrm{E}}_{298 \mathrm{K}}=0$. The standard electrode potential for the reaction $\mathrm{AgI}+{\mathrm{e}}^{-}⟶\mathrm{Ag}+{\mathrm{I}}^{\mathrm{\Theta }}$ is $-0.151 \mathrm{volt}$. Calculate the $\mathrm{pH}$ value.

Three faradays of electricity was passed through an aqueous solution of iron $\left(\mathrm{II}\right)$ bromide. The mass of iron metal (at. mass $56$) deposited at the cathode is -

The ionisation constant of a weak acid electrolyte is $25\times {10}^{-6}$, while the equivalent conductance of its $0.01 \mathrm{M}$ solution is $19.6 \mathrm{S} {\mathrm{cm}}^2 {\mathrm{eq}}^{-1}$. The equivalent conductance of the electrolyte at infinite dilution (in $\mathrm{S} {\mathrm{cm}}^2 {\mathrm{eq}}^{-1}$) will be:

Molar conductances of ${\mathrm{BaCl}}_2, {\mathrm{H}}_2{\mathrm{SO}}_4$ and $\mathrm{HCl}$ at infinite dilutions are ${\mathrm{x}}_1, {\mathrm{x}}_2$ and ${\mathrm{x}}_3$, respectively. Equivalent conductance of ${\mathrm{BaSO}}_4$ at infinite dilution will be:

The limiting molar conductivities $\mathrm{\Lambda }°$ for $\mathrm{NaCl}, \mathrm{KBr}$ and $\mathrm{KCl}$ are $126, 152$ and $150 \mathrm{S} {\mathrm{cm}}^2 {\mathrm{mol}}^{-1}$ respectively. Determine the $\mathrm{\Lambda }°$ for $\mathrm{NaBr}$.

$0.2964 \mathrm{g}$ of $\mathrm{Cu}$ was deposited on passage of a current of $0.5 \mathrm{amp}$ for $30 \min$, through a solution of copper sulphate. Calculate the atomic weight of $\mathrm{Cu}$.

Give your answer by rounding off the value to two significant figures.