Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE MainChemistryIonic Equilibrium

The solubility product constant ( K_ sp ) of Mg(OH) ₂ at 298 K is 4 10⁻⁹ . The solubility of Mg(OH) ₂ in pure water is ________ mg/L . (Nearest integer) (Given molar mass of Mg(OH) ₂ = 58 g mol ⁻¹ )

Correct answer

58

Step-by-step solution

Let the molar solubility of Mg(OH) ₂ be S mol/L . The dissociation reaction is: Mg(OH) ₂(s) Mg ²⁺(aq) + 2 OH ^-(aq) The solubility product expression is: K_ sp = [ Mg ²⁺][ OH ^-]^2 = (S)(2S)^2 = 4S^3 Substitute the given value of K_ sp : 4S^3 = 4 10⁻⁹ S^3 = 10⁻⁹ S = 10⁻³ mol/L To find the solubility in g/L , multiply by the molar mass: Solubility = 10⁻³ mol/L 58 g/mol = 0.058 g/L To convert to mg/L , multiply by 1000 : Solubility = 0.058 1000 mg/L = 58 mg/L Answer: 58

Practice Ionic Equilibrium on Quantrex Academy →

More from Ionic Equilibrium

Given is a concentrated solution of a weak electrolyte A_xB_y of concentration 'c' and dissociation constant 'K'. The degree of dissociation is given by : 2026M₃ A₂ is a sparingly soluble salt of molar mass y g mol ⁻¹ and solubility x g L ⁻¹ . The ratio of the molar concentration of the anion ( A³⁻ ) to the solubility product of the salt 2026Arrange the following resultant mixtures in increasing order of their pH values A. 10 mL 0.2 M Ca(OH)₂ + 25 mL 0.1 M HCl B. 10 mL 0.01 M H₂ SO₄ + 10 mL 0.01 M Ca(OH)₂ C. 10 mL 0.1 202620 mL of a solution of acetic acid required 28.4 mL of 0.1 M NaOH for its neutralization. A solution (X) was prepared by mixing 20 mL of the above acetic acid and 14.2 mL of 0.1 M 2026The pH of a solution obtained by mixing 5 mL of 0.1 M NH₄OH solution with 250 mL of 0.1 M NH₄Cl solution is _____ 10⁻² . (Nearest integer) Given: pK_b(NH₄OH) = 4.74 2 = 0.30 3 = 0. 2026The first and second ionization constants of a weak dibasic acid H₂ A are 8.1 10⁻⁸ and 1.0 10⁻¹³ respectively. 0.1 mol of H₂ A was dissolved in 1 L of 0.1 M HCl solution. The conce 2026At 25°C , 20.0 mL of 0.2 M weak monoprotic acid HX is titrated against 0.2 M NaOH. The pH of the solution (a) at the start of the titration (when NaOH has not been added) and (b) w 2026The solubility product constants of Ag₂CrO₄ and AgBr are 32x and 4y respectively at 298 K. The value of ( molarity of Ag₂CrO₄ molarity of AgBr ) can be expressed as : 2026 Full Ionic Equilibrium list All JEE Main PYQs