# How to calculate solubility of Ca(OH)2?

How do i calculate the solubility of Ca(OH)2 in g/100g of H2O? The ksp i have 2.86x10^-5

Relevance

Ca ( OH)2 <======> Ca 2+ + 2 OH - At the beginning, none of the salt dissolved and at the equilibrium , x moles of the salt dissolved to produce x moles of Ca 2+ and 2x moles of OH- = > ksp = [ Ca 2+][ OH-]^2 => 2.86 ( 10^-5 ) = (x)( 2x)^2 = 4 x^3

=> x = 1.93 ( 10^-2 ) M/ L. The molar solubility of Ca(OH)2 is 1.93 moles / L .The mass of Ca(OH)2 dissolved in water to form 1 L of solution :

(1.93 x 10^-2 mol Ca(OH)2 / 1 L soln ) ( 74 g Ca(OH)2 / 1 mol ) = 1.43 g /L => 0.143 g of Ca(OH)2 / 100 g H2O

• so, Ca(OH)2=> Ca^2+ + 2(OH)^-, ...so Ksp=[Ca^2+]{OH^-}^2 so then basis of one mole solute, yield 2 mole OH, 1mole Ca so them Ksp=[X][2X]^2 do the math plug and chug.

• Ksp = [Ca2+][OH-]^2

using an ICE table for the solubility equilibrium gives

Ksp = 4x^3

solve for x = [Ca2+] = molar solubility of Ca(OH)2

calculate g per liter and hence g per 100g