JEE Main201912 Apr 2019Morning ShiftChemistryIonic EquilibriumActual
What is the molar solubility of A I O H 3 in 0.2 M N a O H solution? Given that, solubility product of Al O H 3 = 2.4 × 10 - 24 :
Options
- A3 × 10 - 19
- B12 × 10 - 21
- C12 × 10 - 23
- D3 × 10 - 22
Correct answer
D. 3 × 10 - 22
Step-by-step solution
Concept of common - i o n will be applicable for O H - group. Al OH 3 ⇌ A l 3+   S          + 3 O H - 3 s + 0.2 K s p for A l O H 3 = 2.4 × 10 - 24 = s 3 s + 0.2 3 Looking at K s p , it is clear that s will be much lesser than 0.2 . Or, s ≪ 0.2 s × 0.2 3 = 2.4 × 10 - 24 ⇒ s = 2.4 × 10 - 24 / 0.008 or, s = 3 × 10 - 22