The specific conductance of $0.0025 \ M$ acetic acid is $5 \times 10^{-5} \ S \ cm^{-1}$ at a certain temperature. The dissociation constant of acetic acid is $...... \times 10^{-7}$. (Nearest integer) Consider limiting molar conductivity of $CH_3COOH$ as $400 \ S \ cm^2 \ mol^{-1}$.

For a strong electrolyte, $\Lambda_{m}$ increases slowly with dilution and can be represented by the equation $\Lambda_{m} = \Lambda_{m}^{\circ} - Ac^{1/2}$. Molar conductivity values of a solution of strong electrolyte $AB$ at $18^{\circ} C$ are given below:

$c \ [mol \ L^{-1}]$	$0.04$	$0.09$	$0.16$	$0.25$
$\Lambda_{m} \ [S \ cm^2 \ mol^{-1}]$	$96.1$	$95.7$	$95.3$	$94.9$

The value of constant $A$ based on the above data [in $S \ cm^2 \ mol^{-1} / (mol \ L^{-1})^{1/2}$] is . . . . . . .

The ionic conductivity of $Ba^{2+}$ and $Cl^{-}$ at infinite dilution are $127$ and $76 \ ohm^{-1} cm^2 eq^{-1}$ respectively. The equivalent conductivity of $BaCl_2$ at infinite dilution (in $ohm^{-1} cm^2 eq^{-1}$) would be $:-$

The metal which is the best conductor of electricity is

The molar conductivity for electrolytes $A$ and $B$ are plotted against $C^{1/2}$ as shown below. Electrolytes $A$ and $B$ respectively are:

Explain the difficulties encountered in the measurement of the resistance of ionic solutions and how to resolve them.