Medium MCQ +4 / -1 PYQ · JEE Mains 2020

The Ksp for the following dissociation is 1.6 × 10–5

$PbC{l_{2(s)}} \leftrightharpoons Pb_{(aq)}^{2 + } + 2Cl_{(aq)}^ -$

Which of the following choices is correct for a mixture of 300 mL 0.134 M Pb(NO3)2 and 100 mL 0.4 M NaCl ?

  1. A Q &gt; K<sub>sp</sub> Correct answer
  2. B Not enough data provided
  3. C Q &lt; K<sub>sp</sub>
  4. D Q = K<sub>sp</sub>

Solution

[Pb<sup>2+</sup>] = ${{300 \times 0.134} \over {400}}$ <br><br> = 1.005 × 10<sup>–1</sup> M <br><br>[Cl<sup>-</sup>] = ${{100 \times 0.4} \over {400}}$ <br><br>= 10<sup>–1</sup> M <br><br>$PbC{l_{2(s)}} \leftrightharpoons Pb_{(aq)}^{2 + } + 2Cl_{(aq)}^ -$ <br><br>Q = [Pb<sup>2+</sup>] × [Cl<sup>–</sup>]<sup>2</sup> <br><br>= 0.1005 × (0.1)<sup>2</sup> <br><br>= 1.005 × 10<sup>–3</sup> <br><br>Given K<sub>sp</sub> = 1.6 × 10<sup>–5</sup> <br><br>$\therefore$ Q &gt; K<sub>sp</sub>

About this question

Subject: Chemistry · Chapter: Equilibrium · Topic: Chemical Equilibrium and Kc, Kp

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