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.
(C)
1. HCl in water is almost 100 percent ionized whereas HCl in is almost unionised. The two solutions have different conductance. Hence conductance depends upon nature of solvent.
2. For strong as well as weak electrolyte, conductance increases with dilution.
3. Conductance does not depend upon nature of electrode used.
4. For same concentration, strong electrolyte has more conductance than weak electrolyte.
For a strong electrolyte, a plot of molar conductivity against is a straight line, with a negative slope, the correct unit for the slope is [2024]
(D)
For strong electrolytes, variation of molar conductivity with concentration (C) is given by:
, where is limiting molar conductivity i.e., molar conductivity at infinite dilution.
From this equation, slope is A.
Substituting units of all terms:
Molar ionic conductivities of divalent cation and anion are 57 S and 73 S respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be: [2024]
(C)
Salt of divalent cation and divalent anion is AB.
It dissociates in water as:
By Kohlrausch's law:
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]
(D)
Consider solution of a weak electrolyte AB with concentration C mol/L, undergoing dissociation in water with degree of dissociation .
is related to and as
Put from II in I
The values of conductivity of some materials at 298.15 K in are The number of conductors among the materials is ___________ . [2024]
(4)
Conductivity at 298.15 K (in ) | Material | Classification |
sodium | conductor | |
glass | insulator | |
graphite | conductor | |
0.1M HCl | conductor | |
Si | semiconductor | |
CuO | semiconductor | |
iron | conductor |
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
(3)
Upon dilution, molar conductivity increases because upon dilution, more of the electrolyte is dissociated and more charge carriers are created. Once all of the weak electrolyte is dissociated (at infinite dilution), then molar conductivity does not increase further and becomes constant at a given temperature. cannot be measured accurately for a weak electrolyte; it is calculated by Kohlrausch law.
The molar conductivity for electrolytes A and B are plotted against 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
(3)
[IMAGE 227]