Which of the following happens when NH ₄ OH is added gradually to the solution containing 1 M A ²⁺ and 1 MB ³⁺ ions? Given : K _ sp [ A ( OH )₂ ]=9 10⁻¹⁰ and K _ sp [ B ( OH )₃ ]=27 10⁻¹⁸ at 298 K .

Step-by-step solution

Condition for precipitation Q _ ip > K _ sp For [ A ( OH )₂ ] aligned & [ A ²⁺ ][ OH ]^2>9 10⁻¹⁰ & [ ~A ⁺² ]=1 M & [ OH ⁻ ]>3 10⁻⁵ M aligned For [ B ( OH )₃ ] aligned & [ B ³⁺ ] [ OH ⁻ ]^3>27 10⁻¹⁸ & [ ~B ³⁺ ]=1 M & [ OH ⁻ ]>3 10⁻⁶ M aligned So, B ( OH )₃ will precipitate before A ( OH )₂