AgNO3 (aq.) was added to an aqueous KCl solution gradually and the conductivity of the solution was measured. The plot of conductance ( Λ ) versus the volume of AgNO3 is
(A)(P)
(B)(Q)
(C)(R)
(D)(S)✓ Correct
Answer: (D)
Solution
The reaction is:
AgNO3+KCl(aq)→AgCl(s)+KNO3(aq)
Initially, there is aqueous KCl solution. As AgNO3 solution is added, AgCl(s) precipitates out. The conductivity remains almost constant (or slightly increases) because the formation of KNO3 compensates for the removal of KCl.
After the equivalence point, excess AgNO3 is added, causing conductivity to increase more rapidly. This corresponds to plot (S).
JEE Advanced · 2011 · 10 Apr 2011 · Paper 1 · Single correct option