Question

Consider these compounds:

A. BaCrO4

B. FeCO3

C. Zn(OH)2

D. Ag2CrO4

Complete the following statements by entering the letter(s) corresponding to the correct compound(s). (If more than one compound fits the description, include all the relevant compounds by writing your answer as a string of characters without punctuation, e.g, ABC.)

Without doing any calculations it is possible to determine that iron(II) hydroxide is more soluble than ______ , and iron(II) hydroxide is less soluble than ______ .

It is not possible to determine whether iron(II) hydroxide is more or less soluble than ________ by simply comparing K_sp values.

Answer 1

The answer will be as below:

iron(II) hydroxide is more soluble than Zn(OH)2 (C) , and iron(II) hydroxide is less soluble than FeCO3 (B) and Ag2CrO4(D) .

It is not possible to determine whether iron(II) hydroxide is more or less soluble than BaCrO4 (A) by simply comparing K_sp values.

Now the solution and procedure to solve:

Solubility product constants are used to describe solutions of ionic compounds of low solubility. Ksp (Solubility product constant) is the equilibrium between a solid and its ions in the solution. For example for Lead chloride K_sp can be written as:

PbCl₂(s) --> Pb²⁺(aq) + 2 Cl^-(aq)

K_sp = [Pb²⁺][Cl^-]²

Here,

Ksp of Ag2CrO4 = 1.1 * 10^ (-12)

Ksp of Zn(OH)2 = 5.0 * 10^(-17)

Ksp of FeCO3 = 3.13*10^(-11)

ksp for BaCrO4 = 1.2*10^(-10)

Ksp for Fe(OH)2 = 1.6* 10^(-14)

The answer will be as below:

iron(II) hydroxide is more soluble than Zn(OH)2 (C) , and iron(II) hydroxide is less soluble than FeCO3 (B) and Ag2CrO4(D) .

It is not possible to determine whether iron(II) hydroxide is more or less soluble than BaCrO4 (A) by simply comparing K_sp values.