Q 1 :    

Identify the factor from the following that does not affect electrolytic conductance of a solution.                 [2024]

• The nature of solvent used.

   

• Concentration of the electrolyte.

   

• The nature of the electrode used.

   

• The nature of the electrolyte added.

   

Q 2 :    

For a strong electrolyte, a plot of molar conductivity against ${\left(\mathrm{concentration}\right)}^{1/2}$ is a straight line, with a negative slope, the correct unit for the slope is    [2024]

• $\mathrm{S}$ ${\mathrm{cm}}^2$ ${\mathrm{mol}}^{-1}$ ${\mathrm{L}}^{1/2}$

   

• $\mathrm{S}$ ${\mathrm{cm}}^2$ ${\mathrm{mol}}^{-3/2}$ $\mathrm{L}$

   

• $\mathrm{S}$ ${\mathrm{cm}}^2$ ${\mathrm{mol}}^{-3/2}$ ${\mathrm{L}}^{-1/2}$

   

• $\mathrm{S}$ ${\mathrm{cm}}^2$ ${\mathrm{mol}}^{-3/2}$ ${\mathrm{L}}^{1/2}$ 

   

Q 3 :    

Molar ionic conductivities of divalent cation and anion are 57 S ${\text{cm}}^2{\text{ mol}}^{-1}$ and 73 S ${\text{cm}}^2{\text{ mol}}^{-1}$ respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be:                        [2024]

• $65 {\text{S cm}}^2 {\text{mol}}^{-1}$

   

• $187 {\text{S cm}}^2 {\text{mol}}^{-1}$

   

• $130 {\text{S cm}}^2 {\text{mol}}^{-1}$

   

• $260 {\text{S cm}}^2 {\text{mol}}^{-1}$

   

Q 4 :    

Which out of the following is a correct equation to show change in molar conductivity with respect to concentration for a weak electrolyte, if the symbols carry their usual meaning:                   [2024]

• ${\mathrm{\Lambda }}_{\mathrm{m}}-{\mathrm{\Lambda }}_{\mathrm{m}}^0+{\mathrm{AC}}^{1/2}=0$

   

• ${\mathrm{\Lambda }}_{\mathrm{m}}-{\mathrm{\Lambda }}_{\mathrm{m}}^{°}-{\mathrm{AC}}^{1/2}=0$

   

• ${\mathrm{\Lambda }}_{\mathrm{m} }^2\mathrm{C}+{\mathrm{K}}_{\mathrm{a} }{\mathrm{\Lambda }}_{\mathrm{m}}^{°2}-{\mathrm{K}}_{\mathrm{a}} {\mathrm{\Lambda }}_{\mathrm{m}}{\mathrm{\Lambda }}_{\mathrm{m}}^{°}=0$

   

• ${\mathrm{\Lambda }}_{\mathrm{m}}^2 \mathrm{C}-{\mathrm{K}}_{\mathrm{a} }{\mathrm{\Lambda }}_{\mathrm{m}}^{°2}+{\mathrm{K}}_{\mathrm{a}} {\mathrm{\Lambda }}_{\mathrm{m}}{\mathrm{\Lambda }}_{\mathrm{m}}^{°}=0$

   

Q 5 :    

The values of conductivity of some materials at 298.15 K in ${\text{S m}}^{-1}$ are $2.1\times {10}^3,$ $1.0\times {10}^{-16},$ $1.2\times 10,$ $3.91,$ $1.5\times {10}^{-2},$ $1\times {10}^{-7},$ $1.0\times {10}^3.$The number of conductors among the materials is ___________ .               [2024]

Q 6 :    

A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will                      [2024]

[IMAGE 225]

• depend upon type of electrolyte

   

• increase sharply

   

• remain same or cannot be measured accurately

   

• decrease sharply

   

Q 7 :    

The molar conductivity for electrolytes A and B are plotted against ${\mathrm{C}}^{1/2}$ as shown below. Electrolytes A and B respectively are:                             [2024]

[IMAGE 226]

• A: Strong electrolyte, B: Strong electrolyte

   

• A: Strong electrolyte, B: Weak electrolyte

   

• A: Weak electrolyte, B: Strong electrolyte

   

• A: Weak electrolyte, B: Weak electrolyte