In a conductance experiment, aqueous A g N O 3 solution is added to aqueous K Cl solution gradually and simultaneously the molar conductivity ( λ m ) is measured. The correct plot of λ m versus

Question

In a conductance experiment, aqueous A g N O 3 ​ solution is added to aqueous K Cl solution gradually and simultaneously the molar conductivity ( λ m ​ ) is measured. The correct plot of λ m ​ versus volume of A g N O 3 ​ solution is

TestHub · Accepted Answer

During the conductometric titration of aqueous $K Cl$ with $A g N O_{3}$ , the following reaction takes place:

$A g N O_{3} (a q) + K Cl (a q) \to A g Cl (s) ↓ + K N O_{3} (a q)$

Initially, the conductance of the solution is due to $K^{+}$ and $C l^{-}$ ions. As $A g N O_{3}$ is added, the $C l^{-}$ ions are precipitated as $A g Cl$ , and they are replaced in the solution by $N O_{3}^{-}$ ions.

Since the ionic mobilities (and hence ionic conductances) of $C l^{-}$ and $N O_{3}^{-}$ are nearly the same, the overall conductance of the solution remains almost constant before the equivalence point.

After the equivalence point, all the $C l^{-}$ ions have been precipitated. Further addition of $A g N O_{3}$ introduces excess $A g^{+}$ and $N O_{3}^{-}$ ions into the solution. This increases the total number of ions, leading to a sharp increase in the conductance.

Therefore, the plot of conductance versus the volume of $A g N O_{3}$ added will be a nearly horizontal line followed by a steeply rising line. This corresponds to the graph shown in option (D).

Answer:

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Options:

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