JEE Main 2024 Chemistry question
The pH at which Mg(OH)₂ = 1 × 10⁻¹¹] begins to precipitate from a solution containing 0.10 M Mg²⁺ ions is .
Answer: 9
Solution
Precipitation begins when the ionic product equals : 1 × 10⁻¹¹ = [0.1][OH⁻]², so [OH⁻] = 10⁻⁵ M. pOH = 5 and pH = 14 − 5 = 9.