Electrochemistry 2 Question 19
18. $\mathrm{AgNO}{3}$ (aqueous) was added to an aqueous $\mathrm{KCl}$ solution gradually and the conductivity of the solution was measured. The plot of conductance $(\Lambda)$ versus the volume of $\mathrm{AgNO}{3}$ is
(a) $(\mathrm{P})$
(b) (Q)
(c) $(\mathrm{R})$
(d) $(\mathrm{S})$
(2011)
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Solution:
- $\mathrm{As} \mathrm{AgNO}_{3}$ is added to solution, $\mathrm{KCl}$ will be displaced according to following reaction.
$$ \mathrm{AgNO}{3}(a q)+\mathrm{KCl}(a q) \longrightarrow \mathrm{AgCl}(s)+\mathrm{KNO}{3}(a q) $$
For every mole of $\mathrm{KCl}$ displaced from solution, one mole of $\mathrm{KNO}{3}$ comes in solution resulting in almost constant conductivity. As the end point is reached, added $\mathrm{AgNO}{3}$ remain in solution increasing ionic concentration, hence conductivity increases.
