What is the solubility (in g/L)of aluminum hydroxide at 25°C? The solubility product constant for aluminum hydroxide is 4.6× 10^-33 at 25°C. A)3.6 × 10^-31 g/L B)8.2 × 10^-10 g/L C)2.8 × 10^-7 g/L D)5.3 × 10^-15 g/L E)1.8 × 10^-31 g/L

Question

Quizplus · Accepted Answer

The solubility product constant (Ksp) for the reaction Al(OH)3 ↔ Al3+ + 3OH- is given as 4.6×10^-33 at 25°C.

Let x be the solubility of aluminum hydroxide in g/L. Then, the equilibrium concentrations of Al3+ and OH- ions in solution are also x M (since the stoichiometric coefficients are 1 and 3).

Using the Ksp expression, we can write:

Ksp = [Al3+][OH-]^3

4.6×10^-33 = x × (x)^3

x^4 = (4.6×10^-33)/1 = 4.6×10^-33

Taking the fourth root of both sides:

x = (4.6×10^-33)^(1/4)

x = 2.8×10^-8 M

To convert M to g/L, we need to multiply by the molar mass of Al(OH)3:

x (g/L) = (2.8×10^-8 M)×(78 g/mol)

x (g/L) = 2.2×10^-6 g/L

So, the solubility of aluminum hydroxide at 25°C is 2.2×10^-6 g/L, which is closest to option C: 2.8×10^-7 g/L. Note that option E has a typo in the power of 10 and is not a valid answer.

What Is the Solubility (In G/L)of Aluminum Hydroxide at 25°C