The Ksp for Fe(OH)3 is 1.6x10-39. Calculate the concentration of OH- if the concentration of Fe3+ at equilibrium is 0.0050M in an aqueous saturated solution of Iron(III)hydroxide.
Write the Ksp expression.
Substitute 0.0050 for (Fe^3+) and solve for (OH^-).
To calculate the concentration of OH- in an aqueous saturated solution of Iron(III) hydroxide, we can use the solubility product constant (Ksp). The balanced chemical equation for Iron(III) hydroxide dissolving in water is:
Fe(OH)3(s) ↔ Fe3+(aq) + 3OH-(aq)
From the equation, we can see that for every one Fe(OH)3 molecule that dissolves, one Fe3+ ion and three OH- ions are formed. Therefore, the concentration of OH- at equilibrium is three times the concentration of Fe3+.
Given that the concentration of Fe3+ at equilibrium is 0.0050 M, we can calculate the concentration of OH- as follows:
[OH-] = 3 × [Fe3+]
[OH-] = 3 × 0.0050 M
[OH-] = 0.015 M
Therefore, the concentration of OH- in the aqueous saturated solution of Iron(III) hydroxide is 0.015 M.